In Memoriam of 
CROSBY STUART NOYES 



The bridegixom may forget the bride, 
Was made his wedded wife yeste'en; 
The monarch may forget his crown 

That on his head an hour has been ; 
The mother may forget the child 

That smiles sae sweetly on her knee; 
But I'll rem.ember thee, dear Noyes, 
And a' that thou hast done for me. 

•—WJUiam Robertson Smith. 




< 



fVUlinm K. SmUhf 

U S. 8o4;anic Garden, 



THE 



NATURAL LAWS OF HUSBANDRY. 



JUSTUS VON LIEBIG. 



EDITED BY 

JOHN BLYTH, M.D., 

PROFESSOR OF CHEMISTKT IN QUEEN'S COLLEGE, CORK- 



NEW YORK : 
D. APPLETON AND COMPANY, 

443 & 445 BROADWAY. 
18G3. 






IWmIU) JlUct-vu f|f j^^ 



EDITOR'S PREFACE. 



IN the following work Baron Liebig has given to the 
public his mature views on agriculture, after sixteen 
years of experiments and reflection. The fundamental 
basis of the work is still the so-called Mineral Theory, 
which holds that the food of plants is of inorganic nature, 
and that every one of the elements of food must be jDresent 
in a soil for the proper growth of a plant. The discovery 
of the remarkable power of absorption possessed by arable 
soils has necessarily led to a modification of the views re- 
garding the mode in which plants take up their food from 
the soil. As the food of plants cannot exist for any length 
of time in solution in soils, it is clear that there cannot be 
a circulation of such solution towards the roots, but the 
latter must go in search of food. Hence the great impor- 
tance of studying the ramification of the roots of plants, and 
the mode of growth of the different classes of plants culti- 
vated by man. The first chapter is devoted to the consid- 
eretion of the growth of plants, of the formation of their 
roots, and of their power of selecting food, and the part 
played by the mineral matters which are absorbed. 

If the food of plants is not in solution in the ground, 
we can conceive that those portions of the soil traversed by 
the numerous root ramifications will be more or less ex- 
hausted of food elements, whilst the immediate neighbour- 



4 EDITOK S PKEFACE. 

ing portions are still rich in them. If, therefore, a suc- 
ceeding crop is to grow equally well on all parts of a field, 
there must be a thorougli mixing of the exhausted and of 
the unexhausted portions of soil. This is effected by mechan- 
ical means, by manures, or by certain chemical compounds. 
Hence the necessity of becoming acquainted with the na- 
ture and properties of the soil and subsoil. The second 
chapter is devoted to this subject. 

The soil consists of arable surface soil and subsoil. In 
the former is accumulated the nutriment of plants chiefly 
cultivated for the food of man. This accumulation is 
affected by the absorptive power of the arable soil for 
mineral matters, by which soluble salts are removed from 
solution, and even chemical decomposition of the most 
stable comj)ounds is brought about, and the bases or acids 
are retained by the soil in a firm state of combination. It 
is the presence of food in the soil in this state of phys- 
ical coinhinatlon which is alone available for the nutrition 
of plants. On the abundant or scanty supply of food in 
this state depends the fertility or sterility of a soil. In 
fertile soils food is present also in another form, in which 
it is not immediately available for the nutrition of plants. 
It exists as chemical compounds Avhich are not soluble in 
water, or acids until rendered so by the action of power- 
ful chemical agents, or to a much smaller extent by the 
slower process of the decomposing action of the weather. 
When the food is eliminated by disintegration (by fallow 
and mechanical operations) from this inert state of chem- 
ical combination, it passes into that of physical combination 
with the earthy particles before it is absorbed by the 
plant. Each kind of soil has its own absorptive power for 
causing the food to pass into a state of physical combina- 
tion. When manure is applied, its greater or less disper- 
sion throughout the soil will depend on this power. In 
general it is absorbed and fixed by the upper few inches 



editor's treface. 5 

of the soil, a smaller quantity penetrates to the lower lay- 
ers, and scarcely any at all to the deep layers and subsoil. 
Hence when a subsoQ is exhausted, manure cannot restore 
its fertility. From this peculiar property of soils of ar- 
resting the circulation of solutions of the food of plants, 
arises the necessity of employing means for the distribu- 
tion of food, and for the imiform mixture of the diflerent 
layers of the soil. The manner in which this is effected by 
mechanical operations, by organic matter, by manures, by 
certain chemical salts, &c., is pointed out in chapters sec- 
ond, third, and twelfth. 

The quantity of food in a state oi physical combination 
in any fertile soil is only limited. Continuous cultivation 
without replacement of all the mineral matters removed 
in the crops destroys fertility, either by causing the abso- 
lute loss of the assimilable food, or by altering the proper 
relative proportions between the different elements of food, 
to such an extent that the due growth of all parts of the 
plant is altered. For the successful growth of a plant in 
all its parts, every clement of food is required. Not one 
substance has any superior fertilising power over another. 
The average crop of an ixmuanurcd field is always regu- 
lated by that element of food which is present in minimum 
quantity. The effect of a manure when beneficial is merely 
to increase the relative proportion of this minimum ele- 
ment. If the m,inimum matter was known in each case, 
its direct application would be sufficient to increase the 
fertility of the soil. But as in general this point is not 
ascertained, the aj^plication of farm-yard manure is certain 
in producing a fertilising effect, simply because it is a com- 
plex mixture containing all the food elements of plants, 
and consequently Avhilst supplying other matters which 
are not immediately wanted, it also furnishes the mhdmum 
substance. In chapter fourth, is discussed the question of 
this altered composition of the ground by cultivation. 



6 editor's preface. 

In chapter eleventh, the fact that not one of the ele- 
ments of food by itself possesses any superior nutritive 
value over the others is further discussed. Nitrogenous 
food, like all the rest, must be present if a plant is to grow 
properly, but no excess of this element of food will of 
itself produce more abundant crops. The analyses of soils 
show that they abound in nitrogen. Were all other sources 
of this element wanting, there would still be a continued 
supply provided for in rain and dew, and in the many pro- 
cesses of oxidation going on at the surface of the earth. 
Probably, wherever we have a generation and circulation 
of carbonic acid, there is also a provision for the forma- 
tion of nitrogenous compounds. When Nature thus pro- 
vides for a supply of nitrogen without the aid of man, it is 
likely that exhaustion of all other elements of food in the 
soil will take place by cultivation before this occurs with 
nitrogen. The inefficacy of the mass of nitrogen in the 
soil cannot be attributed to its existing in two forms, in 
one only of which it is assimilable. This is proved by ex- 
periments with soils and with farm-yard manure. When 
the nitrogen of the soil is not available, some other cause 
must be sought for than its existence in a state in which it 
is sparingly assimilable. This cause will be found to be 
the absence of some other elements of food, which, upon 
being supplied, will at once render the seemingly inopera- 
tive nitrogen at once energetic. 

The diminution of the amount of available food ele- 
ments in the arable surface soil, by the cultivation and sale 
of corn, necessitates the restoration of the removed mineral 
matters. This is effected to a limited extent by foreign 
manuring agents, but chiefly by the formation of manure 
by means of fodder plants. By the system of rotation, 
green crops which draw their nutriment from the subsoil 
are introduced between the cereals. By the deep pene- 
trating roots of the former, the mineral matters of the 



EDITOR S PREFACE. 7 

subsoil are absorbed, and in the form of manure are trans- 
ferred to the arable surface soil. But if this process con- 
tinues, and the com and cattle are still sold, and no re- 
placement from without is made of the lost mineral matters, 
the time will arrive, sooner or later, when the subsoil be- 
comes exhausted, and the surface soil having no longer a 
reservoir from Avhich to draw supplies by means of fodder 
l)lants, is also imable to bear remimerative crops. This 
natural progress of the system of farm-yard manuring is 
fuUy discussed in chapter fifth. The reader must not sup- 
pose that the condemnation passed on the system of fann- 
yard manuring is meant to aj^ply to farm-yard manure itself. 
The latter is the type of a valuable manure which cannot 
be replaced in every respect by any artificial mixtures in 
use. The remarks of the author only apply to the falla- 
cious hopes entertained of keeping up permanently the 
fertility of the soil by manure obtained by the system of 
rotation, whilst Ave continue still to sell the corn raised by 
such manure without bringing back to the soil any portion 
of the mineral matter sold with the corn and cattle. 

The excrements of man contain all the mineral matter 
not only of the corn, but also of the cattle sold from the 
land. Could we restore these excrements to the soil, a per- 
fect circulation of the conditions of life for plants and ani- 
mals would be established, and otir fields would be retained 
in a permanent state of fertility. This problem has been 
solved by the Chinese and Japanese. Chinese rural life, as 
it is described by travellers, as well as the report of the 
Japanese system of husbandry given in Appendix G. by 
Dr. Maron, would scarcely lead us to wish for the improve- 
ment of agriculture upon the plan of these Orientals ! The 
requirements of modern civilization would not permit the 
purchase of manuring matter, however valuable, at the cost 
of all domestic comfort. The sewers must, we fear, still 
receive what would be offensive to our English senses. 



8 EDITOR S PKEFACE. 

But can the contents of these sewers not be made avail- 
able ? The great mass of water which necessarily accom- 
panies at present the fertilising matters, renders them of 
comparatively little value when compared with the expense 
of transport. But how to separate and concentrate these 
matters from the water is a problem which is at present 
occupying the earnest attention of scientific and practical 
men. The solutions hitherto proposed are far from satis- 
factory. The future of agriculture is, however, intimately 
connected with the right solution of this great sewage 
question. 

In conclusion, I have only to state that the foreign 
weights and measures have been, when necessary, trans- 
lated into their equivalents in English, but have been left 
unaltered when the point was only one of comparison, 
which could be equally illustrated by the foreign weights. 

J. BLYTH, M. D. 

Queen's College, Cork : 
March 16, 1863. 



PEEFAOE. 



IN the sixteen years which have intervened between this 
work and the sixth edition of my ' Chemistry aj^plied 
to Agriculture and Physiology,' I have had sufficient op- 
portunity to become acquamted with all the obstacles 
which are opposed to the introduction of scientific teach- 
ing into the domain of practical agriculture. Among 
the chief of these may be reckoned the comjjlete sep- 
aration which has always existed between science and 
practice. 

There has generally prevailed an idea that a smaller 
anioimt of uiformation and intelligence is required for agri- 
cultural pursuits than for any other occupation ; nay, that the 
practical skill of the farmer is only likely to be injured 
when he has recourse to science. Whatever requires 
thought and reflection is regarded as theory, which being 
the opposite of practice, must, of course, be of little value. 
The natural result of such opmions is, that when the prac- 
tical man does attempt to apply scientific teaching, he is 
almost invariably a sufferer. He seems altogether to for- 
get that man does not become intuitively acquainted with 
scientific teaching, which, like tlie skilful use of any com- 
plex instrument, must be learned. 

The truth or error of the notions wliich guide our prac- 
l» 



10 PKEFACE. 

tice cannot, however, be regarded as a matter of indiffer- 
ence. 

The more correct ideas -syhicli science has given us of 
the growth of plants, and tlie part played in the process by 
the soil, air, mechanical operations, and manure, is not re- 
garded in the light of an imjDrovement by the practical 
man, simply because his ignorance does not enable him to 
appreciate the information. Unable to find out the con- 
nection between scientific teaching and the phenomena pre- 
sented in his daily pursuit, he naturally comes to the con- 
clusion, from his point of view, that there really exists no 
connection between them. 

The practical agriculturist is guided by facts observed 
in his own neighbourhood for a long jjeriod ; or, if his views 
are more comprehensive, he follows certain authorities 
whose system of husbandry is held to be the best. It never 
enters into his thoughts to submit this system to proof, for 
he has no standard of comparison at hand. What Thaer dis- 
covered to be useful in Moglin was held to be equally so 
for all Germany, and the facts which Lawes found to be 
true on a very small piece of land at Rothamsted have be- 
come axioms for all England. 

Under the dominion of tradition and of slavish submis- 
sion to authority, the practical man has lost the faculty of 
forming a right conception of the facts which daily pass 
before his eyes, and in the end can no longer distinguish 
facts from opinions. Hence, when science rejects his ex- 
planations of any particxdar facts, it is asserted that the 
facts are themselves denied. If science declares that we 
have made progress in substituting for deficient farm-yard 
manure its active ingredients, or that superphosphate of 
lime is no special manure for turnips nor ammonia for 
corn, it is imagined that the utility of these substances is 
contested. 

Long disputes have arisen about misconceptions of this 



PREFACE. 11 

kind. The practical man does not understand the infer- 
ences of science, and considers himself boimd to defend his 
own views. The contest is not about scientific principles, 
which he does not understand, but about the false concep- 
tions he has formed of them. 

Until this contest is ended by agriculturists themsehes 
taking an active part in the matter, science can offer no 
eflectual aid. I am doubtful if this time has yet arrived. 
I built my hopes, however, on the young generation who 
enter upon practice with a different preparation from their 
fathers. As for myself, I have reached the age when the 
elements of the mortal body betray a certain tendency to 
commence a new circle of action, when we begin to think 
about putting our house in o^'der, and must defer to no 
later period what we have still to say. 

As every investigation in agriculture requires a year 
before we shall have aU the facts before us, I have scarcely 
any prospect of living to see the results of my teaching. 
The only thing that remains for me to do, imder these cir- 
cumstances, is to place my vicAvs in such a manner be- 
fore the public, that there can be no possibility of mis- 
conception on the part of those who will give them- 
selves the trouble of becoming thoroughly acquainted 
with them. 

Many have reproached me with unjustly condemning 
modem agriculture as a system of exhaustion. From the 
communications addressed to me by many agriculturists as 
to their system of husbandry, I must exempt them from 
such an accusation. There are, however, but few among 
the general body who really know the true condition of 
their soil. 

I have never yet met with an agriculturist who kejDt a 
ledger, as is done as a matter of course in other industrial 
pursuits, in which the debtor and creditor accoimt of every 
acre of land is entered. 



12 PKEFACE. 

The opinions of practical men seem to be inherited 
like some inveterate disease. Each regards agriculture 
from his own narrow point of view, and forms his con- 
clusions of the proceedings of others from what he does 

himself. 

JUSTUS VON LIEBIG. 

McNicn : March, 1863. 



COI^TEE^TS. 



CHAPTER I. 

THE PLANT. 



Chemical and cosmic conditions of the life of plants— Conditions for the germina- 
tion of the eeeil , moisturo and oxygen, their action— Influence of the seed in 
the formation of the organs of absoriitiou, and the production of varieties ; 
influence of climate and soil in producing varieties— Importance of a knowl- 
edge of the developement of roots , radication of diflerent plants— Comparison 
of the process of vegetation in annual, biennial and perennial jilants — Growth 
of the asparagus, as an example of a perennial plant ; storing of reserved food 
in its luulerground organs ; use of this store — Meadow and woody plants- 
Growth of biennial plants ; turnips : Anderson's experiments— Growth of an- 
nual plants ; summer plants : tobacco ; winter wheat, its developement like 
biennial plants ; oats ; Arendt's experiments ; Knopp's experiments with 
maize in flower— The protoplastem (matter for forming cells) ; conditions for 
its formation ; Boussingauli's experiments ; organic processes in plants, di- 
rected to the formation of the protoplastem- Absorption of food by plants not 
an osmotic process , marine-plants ; duck-weed ; laud plants ; Hale's experi- 
ments on absorption by the roots and evaporation from the leaves— Power of 
the root to exclude certain substances from absorption not absolute ; Forch- 
hammer, Knopp— Comportment of the roots of land and water plants to solu- 
tions of salts ; De Saussure, Schlossbergor ; comportment of land-plants to so- 
lutions of salts in the soil— Use of those mineral matters which are constant in 
different species of plants , iron, magnesia, iodine, and chlorine compounds — 
Absorption of matters by plants from the surrounding medium ; influence of 
the consumption of them by the plant ; part played by the roots in their ab- 
sorption, ......... PAGE 19 

CHAPTER n. 

THE SOIL. 

The BOil contains the food of plants — Soil and subsoil ; conversion of the latter into 
the former— Power of the pMI Io withdraw the food of plants from solution in 



14 CONTENTS. 

pure and in carbonic acid water ; similar action of charcoal ; process of surface 
attraction ; chemical decomposition often accompanies this attraction of the 
food of plants in the soil ; general resemblance of the soil in its action to ani- 
mal charcoal — All arable soils possess the power of absorption, but in diflerent 
degrees — Mode of the distribution of the food of plants in the soil ; chemically 
and phj'sically fixed condition of the food — Only the physically fixed are avail- 
able to plants, being made soluble by the roots — Power of the soil to nourish 
plants ; on what dependent— Comportment of an exhausted soil in fallow — 
Means for making the chemically fixed elements of food available to plants — 
Action of air, weather, decaying organic matters and chemical means — Distri- 
bution of phosphoric and silicic acids ; influence of organic matters— Action of 
lime— Process of the absorption of food from the soil by the extremities of the 
roots— Mechanical preparation of the soil ; its influence on the growth of 
plants ; chemical means for preparing the soil — Rotation of crops ; its influ- 
ence on the quality of the soil ; action of draining — Plants do not receive their 
food from a solution circulating in the soil ; examination of drain, lysimeter, 
spring and river water ; bog water, food of j>lants contained in it ; Briickenauer 
spring water contains volatile fatty acids ; amount of food of jilants in natural 
waters dependent on the nature of the soil through which they flow— Mud and 
bog earth as manure , explanation of their action— Manner in which plants 
take up their food from the soil ; experiments on the growth of plants in solu- 
tions containing their food ; similar experiments with soil containing the food 
in a physically fixed state — Intimate connection of natural laws — Average 
crop ; necessary quantity of assimilable food in the soil for the production of 
such ; importance of the extent of surface of the food in the soil ; the root sur- 
face—Quantity of food for a given surface of roots necessary for a wheat or 
rye crop — Analysis of the soil of a field- DilTerence between fertility and pro- 
ductive power of a field — Mode of estimating relative extent of root surfaces 
— Conversion of rye into wheat soil ; quantity of food necessary for the pur- 
pose ; the plan impracticable— Immobility in the soil of the food of plants ; ex- 
perience in agriculture — Real and ideal maxhnum production — Conversion in 
practice of the chemically fixed food into an available form — Efi"ect of amanure 
depends upon the property of the soil — Improper relative proportions of the 
different elements of food in the soil : eflfect of this upon the diflerent culti- 
vated plants : means for restoring the proper relative proportions, . . 73 



CHAPTER III. 

ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

Manures ; meaning of the term ; their action as food of plants and means for im- 
proving the soil— Eflect on soils with diflerent powers of absorption— Each soil 
possesses a definite power of absorption ; the distribution of the food of plants 
in the soil is inversely to the power of absorption ; means of counteracting the 
absorptive power — Absorption number, notion of; comparison of in diflerent 
fields ; its importance in husbandry — Soil saturated with food of plants ; its 
comportment with water— Quantity of food to saturate a soil — A saturated 
soil not required for the growth of plants — Manuring may be compared to the 
application of earth saturated with food— Importance of the uniform distribu- 
tion of food in manures ; fresh and rotted stall manure ; compost ; importance 
of powdered turf for the preparation of manure — Quantity of food in un- 



CONTENTS. 15 

manured fields and their powers of production ; increase of tbc latter appar- 
ently out of proportion to the manure added , experiments on this point ■ 
explanation ; composition of the soil and its abeorptivu power compared with 
the requirements of the plants to be cultivated on it ; surface and subeoil 
plants, the tillage and manurirg respectively required by each — Clover 
BlcknesB ; csperimonts of Gilbert and Lawes , their conclueioris ; value of 
them, ......... 134 



CHAPTER IV. 

FARM-YARD MANURE. 

The fertility of a soil depends upon the sum of available food, the continuance of 
the fertility upon the total amount of all food in it— Chemical and agricultural 
exhaustion of the soil — Exhaustion of the soil Ijy cultivation, laws regulating 
its progression ; effect of the transformation in the soil of the chemically fixed 
into physically fixed elements of food ; effect on the progress of exhaustion by 
partial restoration of the withdrawn food of plants— Progress of the exh.austion 
by different cultivated plants — Cultivation of cereals, consequence of removing 
the grain and leaving the straw in the soil ; intervening clover and potato 
crops , effect of leaving in the ground the whole or a X'ortion of tliese crops ; 
division of soils ; productive power of wheat fields increased by accinnulating 
in them the materials derived from clover and potato fields ; cultivation of 
fodder plants ; their food partly derived from the subsoil , addition of tliese in- 
creases the productive power of the surface soil — Natural connection between 
the cultivation of cereals and fodder plants, the influence on the fertility of 
laud— Exhaustion of the soil removed by the restoration of tho withdrawn 
mineral constituents ; the excrement of men and animals contains these ; their 
restoration depends upon the agriculturist, ..... 164 



CHAPTER V. 

THE SYSTEM OF FARM-YARD MANrRING, 

Questions to be solved— Experiments of Renning, their significance— Produce of 
unmannred fields— Influence of preceding crops, of the situation, and climatic 
conditions, on the produce— Each field possesses its own power of production 
— Large crops, their dependence and continuation — Closeness of tho food of 
plants, what is meant thereby — The closeness of the particles of food in the 
soil is in proportion to the produce— Produce of corn and straw influenced by 
the relations of the assimilated food and by the conditions of growth ; action 
of food supplied in manures- Potatoes, oats, and clover crops of the Saxon 
fields ; conclusions drawn from them as to the condition of the fields— Produce 
of these fields from farm-yard manure ; the increase of produce cannot be cal- 
culated from the amount of manure used— Restoration of the power of produc- 
tion of exhausted fields by tho increase of the necessary elements of food pres- 
ent in the soil in minimum amount ; advantageous use of farm-yard manure 
in this respect ; explanation of the result— Action of manure as compared with 
quantity used : experiments— Rational system of cultivation— Depth to which 
the food of plants penetrates is dependent on the power of absorption of the 



16 CONTENTS. 

BOil ; tbe Saxon fields cousiderod in this rei?i)ect ; the power of absorption con- 
sidered iu manuring — Oliaugo produced in tlio compositioa of ttie soil by tlie 
Bystem of farm-yard manuring ; tlie diflbrent stages of tliis system, the fiua^ 
result — Examples of tliesc stages ia the Kaxou experimental fields — Cause of 
the growth of weeds ; remedies — The history of husbandry, what is taught by 
it — Present condition of European husbandry— Present production of the land 
compared with the earlier ; conclusions — Continuation of production regulated 
by a natural law — Law of restoration ; defective practice of it— Agricul'.ure in 
the time of Charlemagne — Agriculture in the Palatinate — Corn fields in the 
valleys of the Nile and Ganges ; nature provides in them for the restoration of 
food of plants — Practical agriculture and the law of restoration — The sta- 
tistical returns of average crops aflbrd an explanation of the condition of corn 
fields, 184 

CHAPTER VI. 



Composition compared with that of seeds ; small amount of potash in it ; its ac- 
tion — Guano and bone-earth, similarity of their active ingredients — Guano 
acts quicker than bone-earth, or a mixture of the latter and ammoniacal salts , 
reason of this — Oxahc acid in Peruvian guano ; the phosphoric acid rendered 
soluble by its means — Peruvian guano, its effect on the cultivation of corn — 
Moist guano loses ammonia— Moistening guano with water acidulated with 
sulphuric acid ; effect — Inactivity of guano in dry and very wet weather — 
Rapidity of its action as a mauurf:, oa what dependent— Comparison of the 
effect of farm-yard manure and guano ; effect produced by mixing the two — 
Guano on a field rich in ammonia — Increased produce by guano, what it pre- 
Bupposes— Exhaustion of the soil by continuous use of guano— Mixture of 
guano with gypsum and with sulphuric acid— The Saxon agricultural experi- 
ments ; their results, ........ 245 



CHAPTER VII. 

POUDRETTE HUMAN EXCREMENTS. 

Poudrette, nature of , small amount of the food of plants in it— Human excrement, 
its value— Construction of the privies in the barracks at Rastadt— Calculation 
of the amount of corn produced by the excrement collected ; importance to the 
neighbourhood— Its eflect not impaired by deodorising with sulphate of iron — 
The excrement of the inhabitants of towns as manure— Its importance, . 258 

CHAPTER VIII. 

EARTHY PHOSPHATES. 

High agricultural value of phosphates— Phosphates of commerce ; selection of the 
kind to be used dependent ontheobteet in view, and on tlio nature of the soil— 
The rapidity and the duration of the effect of the neutral and of the eolublo 
phosphate (superphosphate) of lime— The Saxon manuring experiments, 262 



CONTENTS. VI 



CHAPTER IX. 

GROUND RAPE-CAKE. 

Nature and compositiou of ; the diffusibility of its constituents in the soil is com- 
paratively great— Its importance as a manuring agent is small— The Saxon 
agricultural e^iperiments with rape-eake— The inferences from them, . 267 

CHAPTER X. 

WOOD-ASII. 

The amount of the fool of plants in it— Bos-wood ash givc8 only the half of its 
potash readily to water— Convenience in mixing wood-ash with earth before 
applying it— Lixiviated ash, its value— Proper mode of applying ashes as a 
manure, . . . . • • • • • • 272 

CHAPTER XL 

AMMONIA AND NITRIC ACID. 

Source of the nitrogen of plants— Amount of ammonia and nitric acid in rain and 
dew : Bincau, BoussingauU, Knop — Quantity of ammonia in the air— Quantity 
of nitrogenous food lirought to the soil yearly by rain and dew ; more present 
in the soil than is removed by the crops— The general reason for decrease of 
productive power in soils— Classification of manures according to the amount 
of nitrogen ; assimilable and sparingly assimilable nitrogen ; the nitrogen 
theory ; only ammonia according to this theory is wanting ; resemblance to 
the humus theory— Manuring experiments with compounds of ammonia by 
Schattenmann, by Lawcs and Gilbert, by the Agricultural Union of Munich, 
and by Kuhlmann— The cfHcaeyof a manure is not in proportion to its amount 
of nitrogen ; experiments— Large amount of nitrogen in soils : the experiments 
of Schniid and Pierre ; the arable surface soil contains most nitrogen— Form 
of the ammonia in the soil ; Mayer's experiments— Comportment of soil and 
farmyard manure with the alkalies— The inoflcctive nitrogen of the soil made 
effective by the supply of ash-constituents that are wanting— Progress in ag- 
riculture impossible if dependent on a supply of ammoniacal compounds ; re- 
sults of Lawes' experiment with salts of ammonia— The artificial supply of 
ammoniacal manures contrasted with the crops produced and the increase of 
population— Increase of nitrogenous food by natural means ; formation of 
nitrite of ammonia by oxidation in the air according to Sehonbcin— Supply of 
food in excess necessary to produce corn-crops ; reasons — How the necessary 
excess of nitrogenous food for corn may be obtained from natural sources — The 
Bupply of nitrogen in farm-yard manure in the Saxon experiments correspond- 
ed to the crop of clover-hay — Loss of nitrogen in lime soils by oxidation ; 
utility of a supply of nitrogen to such soils— EfTect of nitrogenous food on the 
aspect of young plants ; on potatoes— Empirical and rational systems of agri- 
culture, .......••• 274 



18 CONTENTS. 

CHAPTER XII. 

COMMON SALT, NITRATE OF SODA, SALTS OF AMMONIA, GYPSUM, LIME. 

EflFect of tlieso substiinecs as elements of food ; their effect on the condition of the 
BOil— Kuhlmann'ti experiments with common salt, nitrate of soda, and salts of 
ammonia , experiments with the same substances in Bavaria ; conclusions ; 
these matters arc elements of food ; they are chemical means for preparing the 
soil ; they cause the distribution of the food in the soil in the form proper for 
the growth of plants — Experiments by Pincus with gypsum and sulphate of 
magnesia on clover; decrease of flowers and increase of stem and leaves of 
clover by sulphates ; the crop is not in proportion to the quantity of sulphates 
used — Effect of gypsum not yet explained; indication in the comportment of 
clover soils with solution of gypsum ; such solution disperses potash and 
magnesia in the soil — Manures, their effect not explained by the composition of 
plants produced by them— Composition of the ash of clover manured with dif- 
ferent substances— Effect of lime ; experiments of Kuhlmann and Trager ; 
comportment of lime-water with soils, ...... 316 

APPENDICES. 

Beech leaves and asparagus, their ash-constituents at different periods of growth— 
The amylum of the palm— Motion of sap in plants— Drain, lysimeter, river, and 
bog water, their constituents— Fontinalis antipyrelica from two different waters, 
ash-constituents- Vegetation of maize in solutions of its food— Experiments on 
the growth of beans in pure and prepared turf, results— Japanese agriculture— 
The cultivated soil of the torrid zone, its exhaustibiiity, its manure— Analysis 
of clover by Pincus— Clover sickness, its causes, . . . . 332 



THE 

NATUEAL LAWS OF HUSBANDRY. 



CHAPTEK I 



THE PLANT. 

Chemical and cosmic conditions of the life of plants— Conditions for the gormina- 
tioii of the seed ; nioisluro and oxygen, their action— Influence of the seed in 
the formation of the organs of absorption, and the production of varieties ; 
influence of climate and soil in producing varieties— Importance of a knowl- 
edge of the developement of roots ; radication of difterent plants— Comparison 
of the process of vegetation in annual, biennial and perennial plants— Growth 
of the asparagus, as an example of a perennial plant • storing of reserved food 
in its underground organs ; use of tliis store — Meadow and woody plants- 
Growth of biennial plants ; turnips : Anderson's experiments— Growth of an- 
nua! plants ; summer plants : tobacco ; winter wheat, its developement like 
biennial plants ; oats ; Arendt's experiments ; Knopp's experiments with 
maize in tiower— The protoplastem (matter for forming cells) ; conditions for 
its formation ; Boussingault's experiments ; organic processes in plants, di- 
rected to the formation of the protoplastem — Absorption of food hy plants not 
an osmotic process ; marine-plants ; duck-weed ; land-plants ; Ilale's experi- 
ments on absorption by the roots and evaporation from the leaves — Power of 
the root to exclude certain substances from absorption not absolute ; Forch- 
hammer, Knopp — Comportment of the roots of land and water plants to solu- 
tions of salts ; De Saussure, Schloasbergcr ,• comportment of land-plants to so- 
lutions of salts in the soil — Use of those mineral matters which are constant in 
difterent species of plants ; iron, magnesia, iodine, and chlorine compounds — 
Absorption of matters by plants from the surrounding medium ; influence of 
the coiiBumption of tliem by the plant ; part played by the roots in their ab- 
BorptioD. 

TO obtain a clear view of the tlieory and practice of 
Agriculture, wq must keep in mind the most general 
chemical conditions of the life of plants. ' 

Plants contain combustible and incombustible con- 
stituents. Of the latter, which compose the ash left by 
all parts of a plant on combustion, the most essential 
elements are — phosphoric acid^ sulphuric acid, silicic 
acid, potash, soda, lime, magnesia, iron, and ohionde 
of sodium. 



20 THE PLANT. 

The combustible constituents are derived from car- 
honic acid, ammonia^ sulpharic acid, and water. 

By the vital j^rocess of vegetation, the body of the 
plant is formed from these materials, which are there- 
fore called ihefood of plants. All the materials con- 
stituting the food of our cultivated plants belong to the 
mineral kingdom. The gaseous elements are absorbed 
by the leaves, i\\Q fixed elements by the roots ; the for- 
mer, however, being often constituents of the soil also, 
may reach the plant by the roots, as well as by the 
leaves. 

The gaseous elements form component parts of the 
atmosphere, and are, from their nature, in continual 
motion. The fixed elements are, in the case of land- 
plants, constituents of the soil, and cannot of themselves 
leave the spot in which they are found. The cosmie 
conditions of vegetable life are /leat and sunlight. 

By the cooperation of the cosmic and the chemical 
conditions, the perfect phmt is developed from the germ 
or seed. The seed contains, within its own substance, 
the elements required to form the organs which are in- 
tended to take up food from the air and the soil. These 
elements are nitrogenous substances, similar in compo- 
sition to the casein of milk or the albumen of the blood ; 
and also starch, fat, gum, or sugar, with a certain quan- 
tity of earthy phospliates and alkaline salts. The fari- 
naceous body, or so-called albumen of the seed of corn, 
as also the constituents of the cotyledons in leguminous 
plants, become the roots and leaves of the nascent plant, 
if corn-seeds are set to germinate in water, and allowed 
to grow upon a glass plate furnished with fine perfora- 
tions, through which the roots may reach the water, 
the grain will go on growing for several weeks without 
receiving any incombustible element of food or any 
constituent of the soil. After three or four weeks the 
apex of the fii'st leaf is seen to turn yellow ; and upon 
examining the seed, nothing but an empty skin is found, 
for the starch has disappeared together with the cellu- 
lose (Mitscherlich). However, the plant does not die 
away, but new leaves are produced, often also a feeble 



GERMINATION AND GUOWTII OF THE SEED. 21 

stalk ; the constituents of the first-formed, but now 
M-itliering, letives being applied to the formation of 
fresh shoots. 

Under favourable circumstances, seeds with very 
large and vigorous cotyledons abounding in nutritive 
matter (e. g. beans) may, by vegetation in water alone, 
be got to tiower — nay, even actually to produce small 
seeds ; this developement, however, is mostly unat- 
tended by a perceptible increase of substance, but de- 
pends solely upon a mere transposition of the elements 
of the seed. 

Nutrition is a process by which food is assimilated ; 
a plant grows when its mass is augmented, and its mass 
is increased by absorl)ing materials from without, which 
are, from their nature, suited to become constituent ele- 
ments of the body of the plant, and to sustain those 
functions upon which their assimilation depends. 

The bud on a potato-tuber stands in the same rela- 
tion to the constituents of the tuber as the germ in a 
corn-seed does to the farinaceous matter of the albumen. 
"While the bud is developed in the formation of the 
young plant, the amylum and the nitrogenous and min- 
eral constituents of the sap of the tuber are employed 
to form the young branches and leaves. A potato, 
which lay wrapt iip in thick paper, in a box, in the 
Chemical Laboratory at Gicssen — in a place absolutely 
dark, dry, and warm, where the atmosphere was seldom 
changed — was found to have produced, from each bud, 
a simple white shoot many feet long, showing no traces 
of leaves, but covered with hundi-eds of minute potatoes, 
which exhibited the same internal structure as tubers 
grown in a field ; the cells consisted of celhilose, and 
were filled with minute starch granules. It is certain 
that tlie starch of the n^. tlier'tubcr, to have moved 
away from its position, must have become soluble ; but 
it is equally clear that in the developement of the 
shoots a cause was operative within them, which (in the 
absence of all outward causes whereon growth depends) 
reconverted the dissolved constituents of the mother 
tuber into cellulose and starch granules. 



22 THE PLANT. 

The conditions required for tlie germination of a 
seed are — moisture, a certain degree of lieat, and access 
of air ; where one of these conditions is excluded, the 
seed will not germinate. By the influence of the moist- 
ure which the seed absorbs, and which causes it to 
swell, a chemical action iakes place in it ; one of the 
nitrogenous constituents acts upon the others, and upon 
the aniylum, so that by a transposition of the element- 
ary particles, the constituents are rendered soluble ; the 
gluten is converted into vegetable albumen ; the amy- 
lum and oil into sugar. If the oxygen of the air is ex- 
cluded, the changes either do not take place or they 
proceed in a different way. The seeds of land-plants, 
when submersed under water, or placed in a soil cov- 
ered with stagnant water, which excludes the air, will 
not put forth their plumules. This is the cause why 
many seeds, lying deep in the ground or in bogs, will 
remain for many years without germinating, although 
the conditions of moisture and temperature be favour- 
able. It is often found that earth taken up from bogs, 
or brought up by the plough from the deep subsoil, and 
exposed to the atmospiiere, becomes covered with vege- 
tation, arising from seeds which, for their develope- 
ment, required free access of air. Lowness of tempera- 
ture tends to annul or retard the influence of the air 
upon the process of germination ; whilst increase of 
temperature, with a proper supply of moisture, acceler- 
ates the chemical changes in the seed. No seed germi- 
nates below 32'^ Fahrenheit ; each germinates at a defi- 
nite temperature, and therefore in fixed seasons of the 
year. The seeds of Vicia faba, Phaseolxis mdgaris, 
and the poppy, lose the power of germinating when 
dried at 95'^ Fahrenheit ; while barley, maize, lentil, 
hemp, and lettuce seed retain the power at that heat ; 
but wheat, rye, vetch, and cabbage seed will germinate 
even at 158° Fahrenheit. 

During germination, oxygen is taken up from the 
air around the seed, and an equal volume of carbonic 
acid is evolved. 

If seeds are set to germinate in glasses, with a slip 



PROCESS OF GERMINATION. 23 

of litmus paper fastened on the inside, the paper is red- 
dened, ol"ten after a very short time, owing to the dis- 
engagement of acetic acid : the most abundant and 
rapid evohition of free acid was found to take phice in 
the germination of cruciferous phuits, cabbage, and 
rape-seed (Beccjuerel, Edwards). Certain it is that the 
fluid contents of the cells of the roots, as well as the Bap 
of most plants, have an acid reaction, from the presence 
of a non-volatile acid ; the sap of the young spring 
shoots of the vine yields, upon evaporation, an abun- 
dant crystallization of bitartrate of potash. 

By the experiments of Decandolle and Macaire, 
which have not yet been controverted, it was shown 
that vigorous plants of C/wndrllla inuralis and Phaseo- 
lus vulgaris which had been taken from the ground, 
with their roots, and were allowed to vegetate in water, 
imparted to the water, after a week's time, a yellowish 
tint, a smell like that of opium, and a harsh taste : 
whereas Mdien the root was cut off at the stalk and both 
were placed in water, no such substances were given oii' 
as those which the entire plant had yielded. 

Lettuces and other plants, when taken out of the 
gound, and, with their roots previously washed clean, 
are allowed to vegetate in blue litmus tincture, will 
continue to grow in the liquid, apparently at the ex- 
pense of the constituents of the lower leaves, which 
wither away. After three or four days the litmus tinc- 
ture assumes a red colour, which, however, disappears 
again upon boiling the fluid : this would seem to indi- 
cate that the roots had given off carbonic acid. If the 
plants are left longer in the litmus tincture, the latter 
sufiers decomposition, and becomes neutral and colour- 
less, while the colouring matter, separating in flakes, 
gathers round the fibres of the roots. 

The dcvelopcment of a plant depends upon its first 
radication, and the choice of proper seeds is therefore 
of the highest importance for the future plant. A crop 
of the same wheat, reaped in the same j^ear, and from 
the same field, will exhibit differences in the size of 
the grains, some being larger, others smaller ; and 



24 THE PLANT. 

among botli kinds, some when broken up will present a 
mealy, others a horny appearance, the one being more, 
the others less completely developed. The cause is 
this — that the stalks in the same held do not all shoot 
into ear and flower at the same time, and that some of 
them produce seeds much more maturely than others : 
hence the seeds of the one are far more developed, even 
in unfavourable weather, than the seeds of the others. 
A mixture of seeds unequal in their developement, or 
differing in the quantities of amylum, gluten, and inor- 
ganic matters which they severally contain, will pro- 
duce a crop of plants as unequal in their developement 
as the original seeds from which they sprung. 

The strength and number of the roots and leaves 
formed in the process of germination are (as regards the 
non-nitrogenous constituents) in direct proportion to the 
amount of amylum in the original seed. A seed poor 
in amylum will, indeed, germinate in the same fashion 
as another seed abounding in it ; but by the time the 
former has succeeded, by the absorption of food fi'om 
without, in producing roots and leaves as strong and 
numerous, the plant grown from the more amylaceous 
seed is again just as much more advanced in growth : 
its food-absorbing surface was larger from the begin- 
ning, and the growth of the young plant is in like pro- 
portion. 

Poor and sickly seeds will produce stunted plants, 
which again will yield seeds bearing in a great measure 
the same character. 

The horticulturist knows the natural relation which 
the condition of the seed bears to the production of a 
plant, which is to possess all or only some properties of 
the species : just as the cattle-breeder, who, with a view 
to propagation and increase of stock, selects only the 
healthiest and best-formed animals for his purpose ; the 
gardener is aware that the flat and shining seeds in the 
pod of a stock gilly-flower Avill give tall plants with 
single flowers, while the shrivelled seeds will furnish 
low plants with double flowers throughout. 

The influence of soil and climate gives rise to differ- 



IMPORTANCE OF GOOD SEEDS. 25 

ent variotics of plants, M'hicli, like races, arc possessed 
of certain peculiarities, and are propagated by means 
of seed, as long as the conditions remain the same. 
Planted in another soil, or in a difl'erent climate, the 
new variety Avill lose again some one or other of its dis- 
tinguisliing characteristics. 

Tlie influence exerted by the condition of the soil in 
producing varieties of plants is observed most fre- 
quently with seeds that pass undigested through the 
intestinal canal of animals which have eaten them, and 
then receive a different manuring according to the 
various nature of the excrements of divers animals with 
which they are returned to the soil : an instance is 
afforded by the Byrsonmia verhascifolia (v. Martins). 

In the selection of seeds for planting it is always 
important to take into account the soil and climate 
from which they have been derived. In England seed- 
wheat from a poor soil is considered particularly well 
suited to a rich soil ; rape-seed grown in colder regions 
or situations is sure to give a good crop in warmer 
localities. Clover seed and oats from mountainous dis- 
tricts are preferred to the same seeds from plains. 
Wheat from Odessa and from South Hungary is es- 
teemed in colder regions also. The planters on the 
Upper Rhine import their hemp-seed from Bologna 
and Ferrara. 

In like manner many German flax-growers, who 
wish to produce tall plants of uniform size, attach par- 
ticular value to linseed from Courland and Livonia, 
where the soil and the nature of the climate, especially 
the short hot summer, bring the flowering and fruit 
time near together ; so that the flowers, being simulta- 
neously and uniformly tructifled, produce ripe and per- 
fect seeds. 

Everyone knows how much the weather, during the 
flowering period, influences the formation of seed. If, 
after the flowering has commenced, cold weather or 
rain sets in, retarding the full developement of the in- 
florescence, the flowers fertilised at a later period pro- 
duce no seeds, as the nutriment needed by them is 



26 THE PLANT. 

applied by the flowers first fertilised for their own de- 
velopemeiit. It is a fact, that many plants will not 
repay tlie trouble of cultivation, if the climatic condi- 
tions are not sufiiciently favourable to eifect the 
thorough ripening of all tlie flowers, but serve only to 
ripen part of them. 

With oats it often happens that in warm moist 
weather side-branches will spring from the axils of the 
leaves, when the principal culm is already shooting 
into ear ; whence it happens, that at the end of the 
period of vegetation the plant is found to bear both 
ripe and unripe seeds. 

The condition of the soil, as to porosity or compact- 
ness, influences the radication of plants. The tine fila- 
ments of the root, which are often coated with cork-like 
matter, are lengthened by the formation of new cells at 
their extremities, and they are obliged to exert a certain 
pressure, to force their way through the particles of 
earth. 

The root-fibrils will always extend in that direction 
in which they encounter the least resistance ; and this 
lengthening necessarily presupposes that the pressure 
wherewith the new-formed cells push aside the particles 
of earth, must be somewhat greater than the cohesion 
of the particles. The strength with which the root- 
fibres force their way through the soil, is not equally 
great in all plants. Those plants which have roots 
formed of very fine fibres are but imperfectly developed 
in stiff, heavy soils, wherein other plants with thicker 
and stiffer root-fibres will grow luxuriantly. The very 
resistance Avhich the heavy soil opposes to the spreading 
of the roots of such plants tends to strengthen their 
fibres. 

Of the cereals, wheat, with a comparatively feeble 
ramification of roots in the upper layers of the soil, still 
forms the strongest roots, which often penetrate several 
feet down into the subsoil ; for a certain degree of com- 
pactness in the surface soil is favourable to the devel- 
opement of its roots. There are instances on record, 
where parts of a wheat-field had been trampled down 



EADICATION OF PLANTS. 27 

in the winter by hor?cs (by no means an nnconimon 
occurrence in the foxlumting districts of England), so 
far as to destroy every trace of a wheat-plant, and yet 
next year's crop turned out nnich more abundant on 
those very spots than in any other part of the field. It 
is evident that, to outlive an attack of this kind, a plant 
must have its principal roots spreading in the deeper 
layers of the soil. In the devclopement of its roots and 
the power of penetrating the deeper layers of the soil, 
the oat-plant stands next to wheat, and will flourish in 
a somewhat stifif soil ; but as in the superficial layers 
also the roots of oats throw out a number of fine feed- 
ers, in a lateral direction, it is necessary that the top- 
soil should be rather light and open. A light, open 
loam, even if of no great depth, is particularly suited 
for barley, which forms a net-work of fine comparatively 
short root-fibres. Peas require a loose soil, with little 
cohesion about it, which will favour the spreading of 
the soft root-fibres in the deeper layers also ; whereas 
the strong woody roots of the horse-bean will ramify in 
all directions, even in a heavy and more compact soil. 
Clover, grass-seeds, and small-sized seeds in general, put 
forth at first feeble roots of small extent, and require so 
much the greater care in preparing the soil, in order to 
ensure their healthy growth. The pressure of a layer 
of earth half to one inch thick suffices to prevent the 
developeraent of the seed, sown in the ground. Such 
seeds require only just as much earth to cover them as 
will retain the needful moisture for germination. It is, 
therefore, found advantageous to sow clover together 
with corn of some kind ; for as the corn is earlier and 
quicker in growth, its leaves shade the young clover 
plant, and protect it from the too intense action of the 
sun's rays ; thus afibrding more time for the extension 
and devclopement of the roots. The nature of the 
roots* of rapes, turnips, and tuberous plants, clearly 
jioints out the part of the soil from which they draw 
their chief supply of food. Potatoes are formed in the 

* Whenever the term 'root' is used in this work, the underground 
organs of plants are meant. 



28 THE PLANT. 

topmost layer of the soil ; whereas the roots of beets 
and turnips, sending their ramifications deep into the 
subsoil, will succeed best in a loose soil of great depth. 
Still, they will also grow well in soil naturally heavy 
and compact, which has been properly prepared for 
their reception. Among turnips, the Swedish variety 
is distinguished by the numerous fibres which the root- 
stock sends into the ground ; and mangelwurzel, with 
its strong and rather woody root-fibres, is still better 
suited than Swedes for a heavy clay soil. 

On the length of roots but few observations have 
been made. In some cases it has been found that 
lucerne will grow roots thirty feet, rape above five feet, 
clover above six feet, lupine above seven feet In length. 

A proper knowledge of the radication of plants is 
the groundwork of agriculture ; all the operations 
which the ftxrmer applies to his land must be adapted 
to the nature and conditions of the roots of the plants 
which he wishes to cultivate. On the root he should 
bestow his whole care ; upon that which grows from it 
he can no longer exert any influence ; therefore, to 
secure a favourable result to his labours, he should pre- 
pare the ground in a proper manner for the develope- 
ment and action of the roots. The root is not merely 
the organ through which the growing plant takes np 
the incombustible elements of food required for its 
increase, but it may, in another not less important 
function, be compared to the flywheel in an engine, 
which gives regularity and uniformity to the working. 
It is in the root that the material is stored up to supply 
the growing plant with the needful elements for con- 
ducting the processes of life, according to the require- 
ments made upon it by the action of light and heat. 

All plants which give landscapes their peculiar 
character, and clothe the plains and mountain slopes 
with perennial green, have an underground develope- 
ment, according to the geological or physical condition 
of the soil, admirably adapted to their perennial exist- 
ence and propagation. 

Whilst annuals are propagated and multiplied by 



KADICATION OF DIFFERENT PLANTS. 29 

seeds alone, and have always a true root easily known 
by its simplicity of structure, by the absence of buds, 
and by the comparatively short range of its fibres, the 
turf and meadow ])lants are i)ropaguted by shoots and 
runners of a peculiar nature, and in many of them 
propagation is independent ot the formation of beed. 

As the strawberry, which will in a very short time 
cover extensive tracts of ground, sends forth from the 
stock above the root-bulb shoots in the shape of run- 
ners, which creeping along the ground, and producing 
here and there buds and roots, grow up as independent 
plants, so the perennial weeds, among which are here 
included the meadow and pasture plants, spread in a 
similar manner by corresi)onding underground organs. 
The creeping roots of the couch-grass {TTitlcxim rei)ens)^ 
the sea lyme-grass {Elymiis ai'enar'iusX the trefoil {Tri- 
folium iwatense)^ the common toad-flax {Linaria vul- 
garis), propagate their plants by suckers in all direc- 
tions from the mother-plant. The smooth-stalked 
meadow-grass {Poa pratensis) is propagated by a 
mother-stock, consisting of true roots, rooted runners, 
and creeping suckers ; rye grass {Lollum) puts forth 
root-suckers in a stiff soil, and prostrate stolons in loose 
ground. Cat's-tail grass {Phlemn) is found sometimes 
with bulbous, sometimes with fibrous many-headed 
roots, having a tendency to creep and to form motlier- 
stocks. Timothy-grass grows stalk in the first year ; 
in the second, it forms sometimes bulbous, sometimes 
fibrous many-headed mother-stocks, wdiich send forth 
creepers in all directions. In the same way, meadow- 
grass spreads partly by budding suckers, partly by 
stolons. 

On comparing the vital processes in annual, bien- 
nial, and perennial plants, we find that the organic work 
in perennials is principally directed to the formation of 
the root. 

The seed of asparagus sown during autumn, in a 
fertile soil, will j^roduce next year, from spring to the 
end of July, a plant about a foot high, the stem, twigs, 
and leaves of which from that time forward show no 



30 THE PLANT. 

further increase. The tobacco plant, which is an an- 
nual, would from the same period to the end of August 
have produced a stem several feet high, covered with 
numerous broad leaves ; and the turnip a broad crown 
of foliage. 

But the cessation in the growth of the asparagus 
plant is only apparent ; for from the moment that the 
external organs of nutrition are developed, the root in- 
creases in extent and substance in far greater propor- 
tion to the over-ground organs than is the case with 
the tobacco plant. The food which the leaves have ab- 
sorbed from the air and the roots from the soil, having 
first been transformed into organisable matter, descends 
to the roots, in which there is gradually collected a 
sufficient store to enable the latter to furnish in the fol- 
lowing year from themselves and without the least sup- 
ply of food from the atmosphere the material required for 
the production of a new perfect plant, with a stem half 
as high again and a much greater number of twigs and 
leaves. The organic labour of this new plant, during 
the second year, results in the generation again of 
products which are deposited in the root, and, propor- 
tionately to the greater extent of the organs of nutrition, 
are stored up in much greater quantity than the roots 
had originally supplied. 

The same process is repeated in the third and fourth 
years ; in the fifth and sixth years the store deposited 
in the roots has become sufficiently rich to produce in 
spring, when the weather is warm, three, four, and 
more stems as thick as a finger, with numerous branches 
covered with leaves. 

A comparative examination of the green asparagus 
plant, and of its withering stems in autumn, seems to 
indicate that at the end of the period of vegetation the 
remainder of the dissolved or soluble substances fit for 
future use, then still remaining in the overground 
organs, descend to the root. The green parts of the 
plant are comparatively rich in nitrogen, alkalis, and 
phosphates, whilst in the withered stems these sub- 
stances are found in small quantities only. The seeds 



PERENNIAL PLANTS. 31 

alone retain comparatively large proportions of phos- 
phated earth and alkalis, being nothing else than the 
excess of those substances which the roots do not require 
for the next year. 

The underground organs of perennial plants are the 
economic gatherers of all the vital conditions necessary 
for certain fimctions. If the soil will allow, they always 
collect more than they give out ; they never spend all 
they receive. These plants form their flowers and seeds 
when the roots have collected a certain excess of phos- 
phates, which may be given np without endangering 
the existence of the plant. An abundant supply of 
nourishment, by means of maniu-ing, will accelerate the 
developement of the plant in one or another direction. 
Manuring a sward with ashes will draw from it clover 
plants ; if acid phosphate of hme is employed, French 
rye-grass will spring up in thickly serried blades. 

In all perennial plants, the underground organs are 
usually very much greater in mass and extent than 
those of annual plants. Whilst the roots of the latter 
die every year, the former preserve theirs in a state of 
readiness to absorb food at every favourable oppor- 
tunity. 

The circle from which a perennial plant draws its 
food enlarges from year to year ; if one part of its roots 
finds little nourishment in a given spot, other parts 
draw their supply from other spots richer in the food 
required. 

Only a very small portion of the plants of a thickly 
covered meadow will produce stems ; the far greater 
part will develope only tufts of leaves ; and many will 
for years be confined to the production of underground 
suckers. 

For perennial grass and meadow plants, the produc- 
tion of underground suckers is of the highest impor- 
tance, since by them the plant is furnished with nutri- 
ment at a time when a scarcity of supply would 
endanger the life of annual plants. 

A good soil, and all other conditions of vegetable 
life, will of course exert the same favourable influence 



32 THE PLANT. 

upon j)ei*ennial as on annual plants ; but the develope- 
ment of the former is not so much dependent upon acci- 
dental and passing states of the weather, as is the case 
with the latter. Unfavourable conditions will, indeed, 
check the growth of a perennial plant, but only for a 
time, until a favourable change ensues, when the plant 
will resume growing ; whereas an annual plant, under 
the same circumstances, reaches the limits of its exist- 
ence and dies. 

The permanence of vegetation on our meadows, and 
the certainty of their produce under varying conditions 
of soil and weather, must be attributed to the great 
number of plants which are able to continue for a 
shorter or longer period at a low stage of developement. 
While the one species of plants is developed above 
ground, producing flowers and seeds, a second and third 
species gather below the surface the conditions for a 
similar future growth. The one vegetation seems to 
disappear, to make room for another and a third, until 
for itself too the conditions for a perfect developement 
recur. 

The woody plants grow and are developed in a man- 
ner qidte similar to the asparagus plant, with this dif- 
ference, however, that they do not lose their stem when 
the period of their vegetation comes to an end. An 
oak-sapling, 1^ foot high, was- found to have a root 
above 3 feet long. The stem and the root serve jointly 
as a magazine for storing up the organi sable matter to 
be used next year in restoring all the external organs 
of nutrition. When the stems of lime trees, alders, or 
willows have been cut down, they will, if lying in shady 
moist places, shoot out afresh, often after the lapse of 
years, and produce numerous twigs a foot long or more, 
covered with leaves. 

The pauses which occur in the seed -bearing of forest 
trees are similar to those which are observed in most 
perennial plants, which, when growing on a poor soil, 
will also take several years to collect the conditions 
necessary for the production of fruit (Sendtner, Ratze- 
burg). 



MINERAL MATTERS IN FALLEN LICATES, 33 

The loss of inorganic food-constituents, which the 
fohaceous trees suffer by the fall of the leaves, is trifiiuo;. 
When the leaves have attained their full formation, tlie 
cells of the hark receive a copious supply of amylum, 
which substance completely disappears from the cells 
in the boss of the leaf-stalk (11. Muhl). Even long be- 
fore the fall of the leaves, their sap is considerably 
diminished, while the bark of the branches is, just 
at that time, often actually overflowing with sap 
(H. Mohl). In accordance with this fact, the analysis 
of the ash of the leaves shows that the amount of alkali 
and phosphoric acid in them decreases immediately 
before the fall ; the fallen leaves contain such trifling 
quantities of these constituents, in comparison to their 
mass, that it is difiicult to account for the injurious 
consequences arising from the raking up and removal 
of the fallen leaves in woods. (See Appendix A.) 

A similar reflux of the assimilative products appears 
to take place in the grasses ; when from the intense 
heat of summer the leaves begin to decay, chemical 
analysis reveals in the yellow leaves scarcely any traces 
of nitrogen, phosphates, and alkalis ; and, indeed, ani- 
mals instinctively turn from all kinds of fallen leaves, 
and refuse to feed on them. 

In annuals and biennials the organic action results 
in the production of fruit and seed, after which the 
activity of the root comes to an end ; in perennials, the 
production of seed is rather an accidental condition of 
their permanent existence. 

The biennial can bestow more time than the annual 
in gathering the material necessary for the production 
of seed and fruit, which closes the period of its exist- 
ence ; but the time in which this takes place depends 
upon the state of the weather and the nature of the soil. 

The annual is uniformly developed in all its parts ; 
the food daily taken up is expended in increasing the 
overground and underground organs, which meanwhile 
take up a larger amount of food in proportion to the 
increase of their absorbent surface. With the growth 
of the plant, the conditions of increase inherent in the 



34 THE PLANT. 

plant itself become enlarged, and exert tlieir influence 
in proportion as the external conditions are favourable. 

The developement of the biennial plants cultivated 
for their roots has three distinct periods ; in the first 
period the leaves principally are formed ; in the second, 
the roots, in which are stored the substances needed to 
produce the flower and fruit dming the third period. 

A series of experiments, made by Anderson, upon 
turnips, afibrds a clear view of the several directions in 
which the energy of a biennial plant tends at difterent 
periods of its growth. (' Journal of Agriculture and 
Transactions of the Highland Society,' No. 68, 69, 
new series, 5.) 

These experiments were made to ascertain the total 
produce of vegetable substances obtained from turnips 
on one acre of ground. The turnips were gathered at 
four difi'erent stages of growth ; the first on July 7, the 
second, on August 11, the third, on September 1, and 
the fourth, on October 5. The following table shows 
the weight of leaves and roots in pounds, taken up at 
the end of the respective stages, and calculated upon 
one acre of ground. 

Weight of leaves. Weight of roots. 
I. Harvest after 32 days .... 219 pounds '7'2 pounds 

II. " 67 "... . 12,793 " 2,762 " 

III. ■" 87 " .... 19,200 " 14,400 " 

IV, " 122 " .... 11,208 " 36,792 " 

The relative quantities of leaves and roots show that 
in the first half of the time of vegetation, sixty-seven 
days, the organic labour in the turnip plant is princi- 
pally directed to the production and developement of 
the external organs. 

From the 7th July to the 11th August, a period 
of thirty-five days, we find the increase to be 12,574 
pounds in the leaves, and 2,755 pounds in the roots, 
which gives a daily increase of 

Leaves. Hoots. 

359 pounds. | 78 pounds. 

In this stage, accordingly, the production of leaves 
prevailed over that of roots to this extent, that out of 



OROWTU OF TUKNIPS. 35 

eleven parts of food absorbed by the plants, nine parts 
went to the leaves and only two parts to the roots. 

We find a very different proportion in the third 
stage ; for during twenty days the weight of the leaves 
has increased by 6,507 pounds, that of the roots by 
11,038 pounds, which gives a daily increase of 

Leaves. Eoots. 

323 pounds. | 582 pounds. 

During this third stage the plants take np daily some- 
what more than double the amount of food taken up on 
any given day of the second stage, and this increase 
must stand in proportion to the daily enlargement of 
the surtace of the roots and leaves ; but the food 
ab.-oi'bed is distributed in the plant in a very different 
manner. Of twenty-Uve parts by weight of food ab- 
sorbed and assimilated, nine parts only remain in the 
leaves, the other sixteen parts serve to increase the mass 
of roots. 

In exactly the same ratio as the leaves approached 
the limits of their developement, they lost the power of 
applying to their further growth the food which they 
had absorbed, and which now transformed into organ- 
isable matter was deposited in the roots. The same 
nutritive particles which went to form leaves, so long 
as the mass of foliage kept on increasing, now became 
constituent portions of the root. 

This migration of the constituents of the leaves and 
transformation into constituents of the root appear to be 
most clearly shown in the fourth stage. The total 
weight of leaves, which on the 1st September still 
amounted to 19,200 pounds, had by the 6th October, 
or within the space of thirty-five days, decreased by 
7,992 pounds, that is 228 pounds a day ; in other 
words, out of every thirty-four leaves ten had witheretl, 
M'hile the roots had increased by 22,392 pounds, or GIO 
pounds a day — a daily increase much more considerable 
than during^the third" stage. 

It IS evident that with the advance of autumn, with 
the lower temperature and diminished action of sun- 



36 



THE PLANT. 



light, the organic energy of the leaves decreased, and 
more than a third of the organisable matter collected in 
them descended to the roots, to be stored up for future 
use. 

If we compare the quantities of nitrogen, phosphoric 
acid, potash, common salt, and sulphuric acid, absorbed 
during the last ninety days by the turnips growing on 
one acre of ground, we find from Anderson's experi- 
ments that the daily amount was as follows : — ' 

Absorbed by the entire plant in a day. 



Total increase. 


Second stage. Third stage. 


Fourth stage. 


In substance 


437 
1-15 
0-924 
1-41 
1-12 
0-84 


907 
0-695 
MO 
4-04 
1-57 
1-98 


Pounds. 
417 


Nitrogen 


1-21 


Phosphoric acid 

Potash 

Sulphuric acid 

Salt 


1-25 
3-07 
1-52 
111 



Daily increase of roots in the fourth stage of growth. 





Phosphoric 
acid. 


Potash. 


Sulphuric 
acid. 


Salt. 


Supplied by the soil . . 
" " leaves 


1-25 
0-41 

1-66 


3-07 
1-56 

4-63 


1-52 
0-51 

2-03 


1-10 
0-53 

1-63 



These figures show that the quantity of phosphoric 
acid taken up daily by the turnip plants growing on 
one acre of ground increases from the commencement 
of the second to the end of the fourth stage of growth, 
that is in ninety days from 0*924: to 1"25 pound a-day, 
which reckoned from one day to another makes the 
trifling difference of 0'0037 pound a-day. 

Anderson suspects that his estimate of the nitrogen 
in the leaves during the third stage was not quite cor- 
rect, and that it fell below the actual amount. If we 



PHOSPHOKIO ACID AND TOTASII IN OKOWING TUKNIPS. 37 

add together the quantities of nitrogen absorbed in the 
hist two stages, fifty-live days, we find a daily average 
of 1'03 pound of nitrogen, which is very nearly the same 
as in the preceding stage of growth. 

The quantity of potash increased from the 11th Au- 
gust till the 1st September, in a somewhat higher ratio 
than the amount of vegetable substance produced. 
From the 1st September till the 5tli October the in- 
crease of the roots was nearly double what it had been 
in the preceding stage, but this is explained by the 
migration of the potash compounds from the leaves to 
the roots. It is evident that the increase of potash has 
a certain connection with the formation of sugar and 
the other non-nitrogenous constituents of the roots, but 
no definite proportion can be established between them. 
The absorption of sulphuric acid increased uniformly in 
the three last stages ; that of salt was a little greater in 
the third than in the second and fourth stages. 

"Without wishing to indicate the exact part per- 
formed in the process of vegetation by these various 
mineral substances, as also by lime, magnesia, and iron, 
we remark that, except in the case of potash, the absorp- 
lion of them was evidently uniform from day to day, 
yet showing every day a trifling increase corresponding 
to the daily increase of the food-absorbent surface up to 
the fourth stage of growth. 

The smallest increase was seen in phosphoric acid 
and nitrogen, both equally necessary for the formative 
processes going on in the turnip plant ; and it is mani- 
fest that they must have served to bring into operation 
some more powerful agency, whose effects are revealed 
in the production and augmentation of the non-nitro- 
genous constituents. 

If we take the quantity of mineral substances ab- 
sorbed as the measure of their importance for the 
organic operations going forward in the plant, we must 
assign to sulphuric acid and common salt an influence 
equal to that of any of the others. 

Looking at the qualitii^s of mineral constituents sev- 
erally taken up by the ditierent parts of the plant in the 



38 THE PLANT. 

various stages of growth, Tve observe the greatest dis- 
parities. In the second stage, a quantity of potash, 
amounting in the aggregate to 49*29 pounds, was ab- 
sorbed in 35 days ; ami of this, the roots w^ere found to 
contain 8*02 pounds, equal to one-sixth — the leaves 
41-27 pounds, equal to five-sixths. The same propor- 
tion — namely, about five to one — was found to exist 
between the weight of the leaves produced, and that of 
the roots. 

In the third stage, the vreight of the roots produced 
exceeded that of the leaves ; and of the 80 pounds of 
potash absorbed by the plants, 34 pounds, or more than 
one-third, remained in the roots. The same was found 
to be the case with phosphoric acid, and the other 
mineral constituents ; that is to say, they vrere found 
distributed in varying proportions, corresponding to the 
growth and increase of the mass of the overgroimd and 
underground organs of the turnip plants, which, in the 
various stages, are likewise not imiform. 

If we regard the mere increase of the leaves and 
roots in mineral substances, without reference to the 
total amount of them absorbed by the entire plant, it 
appears to be most irregular, and to proceed by ' fits 
and starts.' The plant receives every day nearly the 
same quantity of phosphoric acid, nitrogen, salt, and 
sulphuric acid, which are distributed in the several 
parts of the plant, leaves, or roots, where they are re- 
quired for use. The chief difierence observable is in 
the increase of potash, which in the third stage is out 
of all proportion greater than that of the other mineral 
constituents. 

it is highly probable that from the raw material — 
i. e. the carbonic acid, water, ammonia, phosphoric acid, 
sulphuric acid, with the cooperation of the alkalis, 
earths, &c. — the chemical process engenders in the 
plant simply a nitrogenous and sulplnu-eous substance, 
belonging to the albumen group, and only one non- 
nitrogenous substance, belonging to the group of hydro- 
carbons. The former retains its character during 
the period of vegetation; while the non-nitrogenous 



NITBOGENODS SUBSTANCES IN TURNIPS. 39 

substance is converted into a tasteless, gum-like body, 
or into cellulose, or sugar — becoming a constituent of 
the leaves or of the roots, according as the organic 
energy preponderates in the overground or under- 
ground organs. 

If tliere is a relation between the phosphoric acid 
and the production of the nitrogenous constituents, the 
soil must contain, in its parts, definite proportioj^is of 
both substances ; and for the cultivation of turnips, the 
upper layers must necessarily be much richer in phos- 
])liates than the lower. For in the first lialf of the 
period for vegetation, the branching of the roots is much 
less extensive than at a later period, and the root is in 
contact with a much smaller bulk of earth than after- 
wards ; hence, if tlie root is to draw from this smaller 
bulk the same amount of nourishment as from the 
larger, the former must contain more of it, in propor- 
tion as the absorbent root-surface is smaller. 

The ash of all plants in whose organism large quan- 
tities of amylum, gum, and sugar are produced, is dis- 
tinguished from the ash of other plants by the prepon- 
derance of potash ; now, if the potash in the sap of the 
turnip plant formed a necessary agent in the formation 
of sugar and the other non-nitrogenons constituents, the 
quantity of that mineral matter absorbed in the thiixl 
and fouVth stages of growth is easily explained — because 
the formation of the non-nitrogenous constituents of the 
root was more active in these than in the former stages. 

That the production of the combustible constituents 
— the conversion of the carbonic acid and ammonia into 
non-nitrogenons and azotised substances — stands in a 
definite relation of dependence to the incombustible 
matter found in the ash, is an opinion which no longer 
requires special proof to support it. But the depend- 
ence is mutual. To say that the reason why the 
azotised or non-nitrogenous products are formed in 
large ])roportion is hecause the plant has taken up more 
phosphoric acid or potash, is just as correct as to assert 
that the plant takes u]) more phosphoric acid or potash 
hfif:axL8e the other conditions required for the production 



40 THE PLANT. 

of azotised or non-nitrogenous substances are found com- 
bined in its organism. 

To enable a plant to attain its maximum of growth, 
the soil must at all times yield, in an available form, 
the whole quantity of each of its constituents ; and, on 
the other hand, the cosmic conditions — heat, moisture, 
and sunlight — must cooperate to transmute the absorbed 
substances into the organs of the plant. If the sub- 
stances that have passed from the soil into the plant 
cannot be turned to account, from the want of this co- 
operation, no fresh substances are absorbed; in un- 
favourable weather, the plant does not grow. No more 
does it grow, even though the outward conditions are 
favourable, if the soil contains no proper nourishment. 

In the second half of the period of developement, the 
roots of the turnip plant, having penetrated through the 
arable surface deep into the subsoil, absorb more potash 
than in the preceding stage. If we suppose that the 
absorbing spongioles of the root reach a stratum of soil 
poorer in potash than the upper layer, or not sufficiently 
rich in that material to yield a daily supply commensu- 
rate with the requirements of the plant, at first, indeed, 
the plant may appear to grow luxuriantly ; yet the 
prospect of an abundant crop will be small, if the sup- 
ply of the raw material is constantly decreasing, instead 
of enlarging with the increased size of the organs. 

In the economy of the turnip, the root receives dur- 
ing the last month of vegetation nearly one-half of all 
the movable constituents of the leaves ; and this consti- 
tutes, after the completion of its first year's period of 
vegetation, a store of organisable matter for future use. 

During the spring of the following year the root 
begins to shoot, putting forth a slight leafy top, and a 
flower-stalk several feet high ; with the developement 
and maturing of the seed, the plant dies. The chief 
bulk of the food stored up in the root is applied, in the 
second year or third period, in quite a difiierent direc- 
tion ; though, beyond the mere supply of water, the soil 
seems to take no part in this new act of life. 

All monocarpous plants — that is, all plants which 



• SUMMER TLANTS. 41 

flower and produce seed but once — present, like the 
turnip plant, distinct periods of life, as regards the 
direction of organic activity in them. In the first, the 
plant ju'oduces the organisahle matter required in the 
succeeding period ; in the latter, that which is required 
for the final functions of life. But these materials arc 
not always stored up in the root, as is the case in the 
turni]) ; in the sago-palm they fill the stem ; in the 
aloe [Agave) they collect in the thick fleshy leaves. 

The production of seed is, with many of these plants, 
much less dependent upon any fixed period of time, 
than upon the store of organisahle matter collected in 
them in the time preceding. Favourable climatic con- 
ditions or propitious weather will hasten, while imfa- 
vourable cosmic conditions will retard, its production. 

The so-called summer-plants are monocarps which 
are able to gather in a few months the conditions re- 
quired for the production of seed. Tlie oat-plant grows 
to matm'ity and bears ripe seed in ninety days; the 
tm'nip-rape only in the second year of its existence ; 
the sago-palm in sixteen to eighteen years ; the aloe in 
thirty to Ibrtv, often not till 100 years. (See Appen- 
dix B.) 

In many perennial plants, the outer part dies every 
year, while the root lives on. In the monocarpous 
plants, the root dies with the production of the seed. 
In these the production of seed is an indispimsalle, 
in tlie perennial plants more of an accidental, condition 
of continued existence. 

The economy of plants is regulated by laws which 
manifest their operation in the peculiar faculty of cer- 
tain organs to store np food for future use ; so that all 
the external causes wliich seem to hinder their develope- 
ment, actually contribute in the end to insure their 
continued existence, ?'. e. their propagation. 

The contents of the roots in perennial grasses and 
asparagus, may, in the different periods of the life of 
tliese i)lants, be compared to the farinaceous body or 
albumen in the grain of cereals ; with this difference, 
however, that the skin does not become empty as is the 



42 THE PLANT. 

case with tlie latter on germination, but is always re- 
filled and keeps increasing in size. The perennial plant 
always receives more than it exj^ends ; whereas the 
monocarpous plant spends its whole store in forming 
fruit. 

The fact that the roots of the turnip, in autumn, 
grow at the cost of the constituents of the leaves, 
readily explains the influence which the removal of 
leaves will exercise upon the crop at different stages of 
growth. The removal of a few leaves in August makes 
no great difference to the root, while the removal of 
leaves at the end of September causes the greatest dam- 
age to the root-crop. Metzler, who made very accurate 
comparative experiments upon this point, found that an 
early cutting of the leaves reduced the turnip crop by 
7 per cent, only, while a late, or a second cutting, re- 
duced it by as much as 36 per cent. 

If, in the first year, instead of the turnips being re- 
moved from the field at harvest, the tops were merely 
cut off and the roots were left and ploughed in, the field 
would, on the whole, sustain a loss of soil constituents ; 
still the roots in the soil would retain the greater por- 
tion of them. A very different relation would arise, if 
at the end of the second year of A^egetation the turnip 
tops were cut off, and the stem were removed together 
with the seed. For, at the end of the first year, the 
root would still retain the far larger portion of the 
azotised and also of the incombustible constituents, 
which would thus be left in the soil ; but in the second 
year these materials would be carried into the over- 
ground part of the plant, and there be used for the 
production of the stem and the seed ; hence, the re- 
moval of the latter would of course make the soil poorer, 
even though the roots were now left in it. Before the 
shooting and flowering, the root was rich in soil con- 
stituents ; after the production of seed, its store of them 
is exhausted. If the plant is cut ofi' and the root left 
in the ground, before flowering, the soil retains the far 
greater portion of the nutritive matter which it had 
given to the plant ; on the contrary, after flowering and 



THE TOBACCO PLANT. 43 

the production of seed, the root retains only a small 
residue of these constituents, and the soil is correspond- 
ingly exhausted of them. 

As it is with the turnip, so is it with culmiferous 
plants. If they arc cut off before flowering, a consider- 
able portion of the nutritive substances stored up in 
them remains in tlie root, which the soil of course loses, 
if the overground plant is removed after the ripening 
of the seed. 

The experience derived from the cultivation of 
tobacco gives a clear view of the processes in the devel- 
opemeut of an annual leafy plant. 

In the tobacco plant the overground and the under- 
ground parts grow with perfect equality; the root gains 
in extent, in the same proportion as the stem lengtliens 
and the leaves increase in number and size. There is 
no appearance of sudden changes in the direction of or- 
ganic activity, no shooting, but the phases of life in the 
plant follow in steady continuous progression. Even 
while the top of the stem bears ripe seeds, and the 
lower leaves have withered, the side shoots of the plant 
are often still putting forth flower-buds, the seeds of 
which will ripen at a much later period. 

The tobacco plant is remarkable for producing in its 
organism two nitrogenous compounds, of which the one, 
nicotine, contains neither sulphur nor oxygen ; while 
the other, albumen, is identical with the sulphureous 
and oxygenised constituents of the cereals and other 
alimentary plants. 

The commercial value of tobacco leaves is in an in- 
verse ratio to the amount of albumen which they con- 
tain, that sort of tobacco being most highly esteemed 
by smokers which contains the least albumen ; for the 
latter ingredient, in the burning of the dry leaves, emits 
on carbonisation a most disagreeable smell of burnt 
horn shavings. The leaves rich in albumen contain, as 
a rule, more nicotine than those which are poor in albu- 
men ; they give the strongest kinds of tobacco, many of 
which cannot be smoked unmixed. 

The tobacco leaves cultivated in France and Ger- 



44 THE PLANT. 

many are manufactured either into smoking tobacco or 
into snuff'. For the fabrication of snuff", leaves which 
are rich in albumen and nicotine are preferred to those 
containing a smaller amount of those ingredients. The 
leaves intended for snuff are, either when still entire or 
after being ground to powder, subjected to a kind of 
fermentation, which takes place pretty speedily, with 
evolution of heat, if they are kept moistened with 
water. From the putrefaction of the albumen there 
arises a considerable quantity of ammonia, which is a 
principal ingredient of German snuff, and is also occa- 
sionally increased by the manufacturers, by moistening 
with carbonate of ammonia or caustic aramonia, to suit 
the taste of consumers. 

The leaves intended for smoking are also improved 
in quality by a slight process of fermentation, which 
serves to diminish the quantity of albumen in them. 

These preliminary remarks will help to explain the 
different methods of cultivating tobacco. 

The size of the leaf in length and breadth, its light 
or dark colour, the height of the stem, the amount of 
produce, and the greater or less proportion of albumen 
and nicotine, all depend very essentially upon the 
manuring of the plant. 

The plant succeeds best, in Europe, on light, sandy, 
humose, loamy, or marly soils. The strongest kinds, 
richest in albumen and nicotine, are grown on virgin 
land, and on heavy clay soil manured with bone-dust, 
shavings and clippings of horns and claws, blood, 
bristles, human excrements, oilcake, and liquid manure. 

In Havannah, tobacco is grown on virgin soil, on 
cleared forest lands, which are often burnt first, as is 
done in Virginia. The best qualities (the poorest in 
albumen) are yielded in the third year of cultiva- 
tion. 

From this it would appear, that animal manure 
^abounding in nitrogen (ammonia) favours the produc- 
tion of nitrogenous constituents; but the soil, on the 
other hand, which is poor in ammonia, and probably 



CULTIVATION OF TODACCO. 45 

contains tlic nitrogen in the form of nitric acid, pro- 
duces leaves containing much less albumen and nico- 
tine. 

The effect of removing the tobacco plant from the 
rearing beds to the field is very striking. Transplanted 
into the new soil, the young tobacco plant proceeds in 
the first instance, like seed in the process of germina- 
tion, to produce roots; the leaves already formed 
wither on trans})lantation, and their movable constitu- 
ents, together with the store of organisable matter col- 
lected in the roots, are applied to the production of 
numerous branch radicles. A second transplantation 
has a still more i'avourable effect upon the underground 
organs of absorption. 

As the direction of the organic operations in sum- 
mer-plants is entirely turned to the formation of seed, 
and as this consumes the materials wliicli give activity 
to the roots and leaves, the tobacco planter breaks out, 
when the plant has put forth six to ten leaves, the heart 
of the middle stem, on which the flowers and seed cap- 
sules groAv. Stripped thus of the crown, the whole 
vigour of the plant is now directed to the buds between 
the leaves and stem, and these put forth side-shoots 
which are treated like the principal stem, that is to say, 
they are either broken away, or simply cracked by 
twisting. Thus the leaves retain the organisable matter 
subsequently produced, and increase in mass and size, 
while the amount of water in them diminishes. By the 
middle of Septeml)er, the leaves lose their green colour 
and are spotted with yellow blotches, imparting a mar- 
bled look ; they become parchment-like, feel dry to the 
touch, get flaccid, with the ends drooping to the ground, 
and, wlien arrived at full maturity, are viscous, clammy, 
and readily come oflf the stem. 

This treatment is variously modified, according to 
the several varieties of tobacco, and the different coun- 
tries in which it is grown. The so-called common Eng- 
lish tobacco, which is particularly rich in nicotine, is 
often allowed by planters to run to seed, in order to 



46 THE PLANT. 

effect a separation of the nitrogenous constituents, the 
albumen forsaking the leaves and lodging in the seed. 

In the young shoots, buds, and generally in all 
parts in which the production of cells is most actively 
carried on, the sulphureous and nitrogenous constitu- 
ents (albumen) accumulate, and thus the younger leaves 
are always richer in these substances than the older. 
The leaves nearest the ground (sand-leaves) give a 
milder, the upper leaves a stronger tobacco. In those 
varieties which are not particularly rich in nicotine and 
albumen, the sand-leaves are of much less value than 
the upper leaves. A mild tobacco always means a 
tobacco poor in narcotic constituents. 

The course pursued by the European tobacco plant- 
er, who lays a superabundance of animal manure upon 
his fields, is the exact reverse of that adopted by the 
American planter, who cultivates his plants upon a 
field that has never been manured. The one seeks to 
reduce or dilute tlie narcotic, sulphureous, and nitro- 
genous constituents of the leaves ; the other to concen- 
trate them. Accordingly, the American planter breaks 
the lower leaves in their full vigour, when the plant 
has attained to half-growth ; the European planter at- 
taches the greatest value to the fully-developed upper 
leaves. 

As the tobacco plant, like all annuals, only yields 
up its whole store of organisable matter at the ripening 
of the seeds, the stem does not die after the loss of the 
leaves ; but the materials still remaining in it and in 
the roots cause the stem to send forth fresh shoots, and 
frequently even leaves, though small-sized ones. In the 
West Indies, Maryland, and Virginia, before the gather- 
ing of the leaves, the stems are notched immediately 
above the ground, so that they lean over without being 
severed from the root. In warm weather, the water in 
the leaves evaporates, and a motion of the sap ensues 
from the stems and roots towards the leaves, in which 
the sap is thus concentrated as the plant withers. The 
tobacco planters on the Khine have found that a supe- 



MODE OF GROWTH OF WINTER-WHEAT. 47 

rior tobacco, poorer in albinnon and nicotine, is pro- 
duced if, instead of breaking the leaves off in the field, 
the plant with the leaves on it is cut down just above 
the ground, and hung up to dry with the top down- 
wards. Tlie stem will, under these circumstances, con- 
tinue to vegetaLC for a time, sending forth small shoots 
which gradually turn in an upward direction and put 
forth Uower-buds. In these flower-buds the sulphureous 
and nitrogenous constituents are collected from the 
leaves, which lose these ingredients in the same propor- 
tion, and are thereby imjjroved in quality. 

Of the plants cultivated for the sake of their seed, 
wheat holds the chief place. 

Winter-wheat is in its developement extremely like 
a biennial plant. In the biennial tm'nip we see that 
with the first leaves a corresponding number of root- 
fibres are produced ; and that after the formation of the 
leaf-top, the root begins to expand greatly in size and 
extent, immediately after which the flower and seed- 
stalk shoots forth. 

Yery soon after winter-wheat is sown, the young 
plant puts forth the first leaves, which in the course of 
winter and the early months of spring increase to a 
tuft ; to all appearance the vegetation of the plant 
seems to cease for weeks and months. When warm 
weather comes, the plant puts forth a soft stem, several 
feet high, furnished with leaves, and bearing at the top 
an ear set with flower-buds in which, after flowering, 
the seeds are formed. As the seed is developed, tlie 
leaves from the bottom upwards turn j^ellow, and die 
with the stem as the seed ripens. 

It cannot be doubted that while the growth of the 
plant appears to have ceased before the time of shoot- 
ing, the over and under ground organs are in constant 
activity ; food is incessantly absorbed, which, however, 
is but partially employed to increase the mass of leaves, 
but not to form the stem. There is, therefore, every 
reason to believe that the far larger portion of the or- 
ganisable matter produced in the leaves during this 



48 THE PLAiirr. 

period goes to the roots, and that this store is after- 
wards applied to the formation of the stalk. On the 
approach of warmer weather all the operations of life in 
cereal plants are quickened, and the quantity of food 
daily absorbed and worked up increases with the extent 
of the absorbing and elaborating organs. In spring 
many of the older leaves and of the root-fibres die in 
the portions of the soil exhausted by them ; tlie root- 
tops send forth new buds, and with every new bud new 
rootlets, until the stalk-joints have attained a certain 
length. From this time forward to the end of the pe- 
riod of vegetation, both the food absorbed by the plant, 
and the movable part of the materials formed in the 
leaves, stem, and root, go to form flowers and seeds. 

The observations of Schubart show tliat the roots of 
cereal plants, in the first period of vegetation, increase 
much more than the leaves. Schubart found that rye 
plants, which, six weeks after sowing, presented leaves 
5 inches long, had meanwhile produced roots 2 feet in 
length. 

The vigour with which cereal plants send forth their 
stalks and side-shoots corresponds to the developement 
of the root. Schubart found as many as eleven side- 
shoots in rye plants, with roots 3 to 4 feet long ; in 
others, where the roots measured If to 2J feet, he lound 
only one or two ; and in some, where the roots were 
but 1^ foot, no side-shoots at all. 

Tlie action of a low temperature in autumn and win- 
ter, which puts a certain limit to. the activity of the 
outer organs, without altogether suppressing it, is essen- 
tial to the vigorous thriving of winter corn. It is a 
most favourable condition for future developement, if 
the temperature of the air is below that of the soil, so 
as to retard for several months the developement of the 
outer plant. 

Hence a very mild autumn or winter operates un- 
favourably upon the future crop, as the higher temper- 
ature encourages the developement of the principal 
stalk before the proper time, which shoots up thin, and 



DIFFERENT STAGES OF GROWTH OF THE OAT-PLANT. 49 

consumes the food which should have served to form 
buds and new roots, or to increase the store of organisa- 
We matter in the roots. Thns stunted in its develope- 
ment, the root supplies less food to the plant in spring, 
as it takes up and gives out less in proportion to its 
smaller absorbent surface and more limited supply 
stored Mp in it ; and it retains the same feeble character 
in the succeeding periods of vegetation. The agricul- 
turist endeavours to meet the ditiiculty by grazing down 
or cutting these feeble plants ; the formation of buds 
and roots hereupon begins anew, and if the external 
conditions are favourable, and the plant has time to 
fill the root with a fresh store of organisable matter, the 
normal conditions of growth are, in the agricultural 
sense, restored.- Summer corn maintains, in the several 
periods of its developement, the same character as win- 
ter corn ; only these periods are of much shorter dura- 
tion. 

Ahrend's study of the oat-plant in its several stages 
of growth is instructive in this respect. He determined 
the increase in combustible and incombustible constitu- 
ents during the following periods : from germination to 
the beginning of shooting (end of the first stage, 18th 
June) ; from this time to shortly before the end of 
shooting (second stage, 30th June) ; immediately after 
flowering (third stage, 10th July) ; the commencement 
of ripening (fourth stage, 21st July) ; finally, to perfect 
maturity (fifth stage, 31st July). On the 18th June 
the plants were on an average 31 centimetei's high (1-^ 
inch), the three lower leaves were nearly expanded, tlie 
two upper leaves were still folded up. Of the stalk- 
joints the three lower alone had an appreciable length 
(1, 2, and 3 centimeters), the three upper had but a ru- 
dimentary existence. Twelve days after (on the 30th 
June) the plant had attained double the height (63 cen- 
timeters) ; and ten days after this again, on the 10th 
July, after flowering, it had reached 84 centimeters. 

1,000 plants respectively produce in grammes : — 

3 



50 



THE PLANT. 



Constituents 



Examined on 



ISth June, i SOth June. 
I. stage. 11. stage 



In 49 days, 
before 

shooting. 



In 12 days, 

stallis full 

grown. 



10th July. 
111. stage. 



21st July. 
IV. stage. 



In 10 days. In 11 days, 
flowering. | fonnation of 
seed. 



81st July 
V. stage. 

In 11 days, 
ripening. 



Combustible. . 
Incombustible. 



Grammes. 
419 
36-G 



Grammes. 
873 
83-48 



Grammes. 
475 
30-33 



Grammes. 
435 
20-34 



Orammes. 
128 
7-18 



In one day. 



Combustible . . . 


8-551 


72-75 


47'50 


39-45 


12-8 


Proportion . . 


1 


8-5 


5-5 


4-6 


1-5 


Incombustible. . 


0-747 


2-79 


3-03 


1-849 


0-318 


Proportion . . 


1 


3-73 


4-06 


2-47 


0-96 



In looking at these figures we must remember that 
Ahrens could only determine wliat the overgromid part 
of the plant had received from the root, not, as Ander- 
son in the case of the turnip, what the whole plant had 
derived from the soil. The great disparity in the in- 
crease of combustible and incombustible substances 
evidently depends rather upon the unequal distribution 
of the materials absorbed, titan upon any disparity in 
the quantity derived from the soil. The whole period 
of developement comprised about 92 days, and we see 
that for more tlian the first half (49 days) the plant re- 
mains stationary at an apparently low stage of growth, 
the foliage alone being developed, and that not fully. 
In tlie next 12 days, from the 18th to the 30tli June, 
the plant gains double the weight of incombustible con- 
stituents, and grows twice as high as in the 49 days 
preceding ; and within this short time, the overground 
parts absorb nearly the same quantity of incombustible 
constituents as they had previously taken up. In fact, 
the plant takes up 8^ times the quantity of combustible 
matter, and 3f times more of ash constituents on one 
day of shooting, than upon one of the 49 previous days. 

We cannot suppose it at all likely that the external 
conditions of nutrition, the supply of food by the atmos- 
phere and from the ground, or the absorptive power of 



GKOWTII OF THE OAT-PLANT. 



51 



the plant, sliould alter and increase, by fits and starts, 
from one day to another. We are led rather to assume 
that the oat-plant is subject in its develupement to the 
same law which we have observed in the case of tlie 
turnip, and that thereibre, in the second half of the first 
stai>;e of growth, the activity of the leaves Mas jji'inci- 
pally directed to the production of organisable matter, 
to be stored up in the root in the shooting stage, and 
then sup])lied to the overground organs of the plant. 
The heightened assimilative or working power of the 
plant, consequent upon the higher temperature and 
brighter sunshine of summer, was attended by a pro- 
portionate increase in the supply of food ; but the rela- 
tive proportion of the soil constituents remained mucli 
the same as in the turnip plant. 

If we compare the respective quantities of potash, 
phosphoric acid,' and nitrogen, which the overground 
parts of the oat-]>lant have received from the root and 
the soil, in the several stages of growth, i. e. to the 
commencement of flowering, thence to incipient ripen- 
ing, and finally to maturity, we find that 1,000 plants 
have received : — ' 





In the I. and II. 
stages, 61 days. 


In the I. and II. 
stages, 21 days. 


In the V. stage, 
10 days. 


Potash 

Nitrc'cn 


Gramme.?. 
34-11 
250 
5-99 


Grammes. 
13-2 
24-9 
6-94 


Grammes. 
0-0 
5-4 


Phosphoric acid .... 


1-33 



These proportions show that the daily increase of 
potash in the overground parts of the oat-plant was 
pretty nearly the same in the 21 days of the 3rd and 
4:th stages, as in the 61 days of the I'st and 2nd. But 
for the phosphoric acid and the nitrogen a very differ- 
ent result is obtained ; we find that tlic quantity of 
these two ingredients which passed into the stalk, the 
ear, and the leaves, amounted in the 21 days of the 3rd 
and 4th stages to as much as in the 61 days of the 1st 
and 2nd stages : in other words, the overfirround organs 



52 THE PLANT. 

of the plant gained of these two ingredients, in the 
flowering and ripening time, three times as mucli each 
day as in the preceding period. 

Of the turnip-plant we know with tolerable certain- 
ty, that from the time when it sends forth a Hower- 
stalk, the constitnents of the stalk, as also those of the 
flowers and the seeds, are for the most part stored up 
in the root, and are supplied therefrom. It is highly 
probable that the corn-plant is similarly circumstanced, 
and that from the flowering to the end of life it is fed, 
though not exclusively, by the root, which from the 
flowering time gives out what it had stored up in the 
preceding period. 

Knop observed that Indian com plants in flower, 
taken out of the ground and placed with their roots 
simply in water, produced ears with ripe seeds ; which 
proves tbat the materials serving for the production of 
seed were already present in the plant at the time of 
flowering. 

It is an established fact that a corn-plant, if cut off 
before flowering, relapses into that lower stage of vege- 
tation of a perennial plant, in wliich the root receives 
more organisable matter than it parts with.* 

The proportions of incombustible constituents and 
of nitrogen severally required by oats and turnips, are 
remarkably difierent both in the aggregate and during 
the various stages of growth. The facts established by 
Anderson for the turnip, and by Ahrends for the oat, 
are indeed not sufiiciently numerous to warrant us in 
deducing any positive law of growth for those two 
plants : still a few inferences may easily be drawn from 
them. The quantities of phosphoric acid and nitrogen 
in the turnip are, at the end of the first year of vegeta- 
tion, nearly in the ])roportion of 1 : 1 ; in oats, on the 
contrary, of 1 : -i. The oat-plant requires to the same 
quantity of phosphoric acid four times as much nitrogen 

* Buckmann (' Journ. of the Royal Agric. Soc.') sowed wheat on a 
field in autumn 1849, which was continually cut down in 1850, so that the 
plants were never allowed to come to flower : they were left in during the 
Avinter 1850-51, and yielded an excellent crop in the year 1851. 



GKOWTH OF TUKNIPS AND OATS COMPAKED. 53 

as the turnip ; and the latter to the same quantity of 
nitrogen four times as much phosphoric acid. 

If the devek)pement of the oat-})hint takes a similar 
course to that of the turnip, tlie former must have ae- 
cunndated in its underground organs before the time of 
shooting a store of organisabie nuitter, similar to that 
hiid u}) by the turnip at the close of the first year of 
vegetation. The mass of organic substances accumu- 
lating in these plants before the developement of the 
flower-stalk is manifestly much larger in the turnip 
than in the oat-plant. The former receives from the 
soil much more ])hosphoric acid and nitrogen ; but the 
turnip had 122 da^'s, the oat-plant only 50 clays, up to 
the period of shooting for extracting these nutritive 
substances from the ground. Now if the turnips and 
oats growing on a hectare (2^V acres) of land had daily 
receiN'cd an equal amount of them, then, all other cir- 
cumstances being the same, the quantity of nutritive 
substances absorbed would be proportionate to the time 
of absorption. In this respect the nature of the root 
makes a great dift'erence, according to the extent of ab- 
sorbent root-surface. The larger root-surface is in con- 
tact with more earthy particles, and can during the 
same time extract more nutritive substances than the 
smaller. The mass of vegetable substance produced, 
and especially the quantity of non-nitrogenous and azo- 
tised materials, depend upon the nature of the plants. 
If the absorbent root-surface of the oat-plant were 2*45 
times greater than that of the turnip, the former would, 
under like circumstances, take up daily 2*45 times as 
much food as the latter, i. e. the oat-plant would absorb 
in 50 days as much as the turnip in 122 days. Thus 
in equal times the power of two plants to absorb food is 
in proportion to their absorbent root-surface. 

The time of vegetation occupied by the turnip-plant 
comprises, in the first year, 120 to 122 days, and termi- 
nates at the end of July in the next year with the pro- 
duction of seed. If we take the whole time of vegeta- 
tion of the tmnip-plant at 244 days, and suppose the 
time of vegetation of the oat-plant extended from 93 or 



54 THE PLANT. 

95 to 244 days, we find that this would give sufficient 
time I'or growing two oat crops, and advancing a third 
half way to maturity ; and a careful investigation might 
perhaps reveal that the quantity of sulphureous and 
nitrogenous constituents produced in the oat-plant is 
not less than that obtained in turnip-plants from an 
equal area of ground. 

In tlie grains of the cereals the quantity of the sul- 
phiu-eous and nitrogenous constituents is to that of the 
non-nitrogenous (the quantity of the blood-making sub- 
stances to the amylum), as 1 : 4 or 5 ; in the roots of 
turnips, or in the tubers of potatoes, as 1 : 8 or 10, In 
the latter, therefore, the quantity of the non-nitrogenous 
constituents is in proportion to the other constituents 
much greater. 

When at a certain temperature the organic process 
of germination begins in a grain of wheat, the embryo 
first sends down a number of rootlets, while the plumule 
rises upward in the form of a short stem, with U\o 
or three complete leaves. Simultaneously with the 
changes taking place in the embryo, the constituents 
of the farinaceous body (albumen) become fluid ; the 
amylum is converted first into a substance resembling 
gum, then into sugar, while the gluten changes into 
albumen, and both together form protoplastem (Naege- 
li's organic food elements), or the food of the cell. The 
fluidity of the new body enables it to find its way to 
the places where the formation of cells is going on. 
The amylum supplies the elements required to form the 
outer wall of the cell ; the nitrogenous matter consti- 
tutes a principal ingredient of the cell contents. Simul- 
taneously with the roots and leaves, small leaf-buds arise 
upwards on the stem-joint, and small root-buds appear 
at the basis of the roots. 

In the protoplastem of the wheat-plant the non- 
nitrogenous matter exceeds the azotised matter as five 
to one. 

Except water and oxygen, no substance from with- 
out takes any part in these processes. What the seed 
loses in carbon by the formation of carbonic acid in 



FIKST GKOWTEl OF- A GKAIN OF WIIKAT. 55 

germination is afterwards recovered almost entirely by 
the young plant. 

The plant developed nnder these circumstances 
barely increases in substance to any appreciable degree, 
even though it may continue vegetating for weeks. 
The organs developed from a grain of wheat weigh all 
together, when dried, no more than the gi-ain did before 
germination. The relative proportion of the non-nitro- 
genous and azotised substances in them is almost the 
same as in the farinaceous body, the constituents of 
which have in reality merely assumed other forms. 
Tlie leaves, roots, stem, leaf-buds and root-buds collect- 
ively represent the constituent parts of the seed, trans- 
formed into organs and apparatus now endued with the 
power of performing certain operations which serve to 
carry on a chemical process, whereby external inorganic 
substances, with the cooperation of sunlight, are con- 
verted into products analogous in all their properties to 
the materials from which these organs themselves arose. 

The organic process of cell-formation presupposes 
the presence of the protoplasm, and is independent of 
the chemical process by which the latter is generated ; 
but this chemical process is indispensable to the con- 
tiimance of the cell-formation. 

In a young plant which has been developed in pure 
water alone, the chemical process must soon come to an 
end for want of the necessary external conditions. Tlie 
leaves and roots in this c^se can do no work as foi'mative 
organs. In the absence of food they generate no products 
upon which the- continued existence of the plant de- 
pends. When they have arrived at a certain state of 
developement, the cell-formation ceases in themselves, 
although it is still continued in the new root-buds and 
leaf-buds. The latter stand to the movable contents of 
the previously existing leaves and roots in the same re- 
lation as the embryo of the wheat-seed to the fai ina- 
ceous body. The non-nitrogenous and azotised constit- 
uents which represent the working capital of the exist- 
ing roots and leaves are transformed as these die into 
new organs, and new leaves are developed at the ex- 



66 THE PLAJSTT. 

pense of the constituents of the old ones. But these 
processes are of short duration ; after a certain number 
of days the young plant dies. The more immediate ex- 
ternal cause of its short duration is the want of food ; 
but another internal cause is the conversion of the non- 
nitrogenous soluble substances into cellulose or woody 
tissue, whereby it loses mobility. With the diminution 
of this soluble substance the most essential condition of 
cell-formation is impaired : when the whole has been 
consumed, the process comes to an end. The withered 
leaves, when burnt, leave behind a certain quantity of 
ash, showing that they retain some mineral matter ; 
there remains in them also a small portion of nitroge- 
nous substance. 

The most remarkable thing in this developement is 
the part performed by the nitrogenous matter of the 
seed, which becomes a constituent element of the root- 
fibres, stems, and leaves, where its agency serves to 
bring about the formation of cells. After the death of 
the first leaves, it becomes a constituent of the new 
ones, performing in them the same part over again, so 
long as there remains materials for cell-formation. But 
the nitrogenous matter itself is not in reality worked up 
in the plant, and forms no actual tissue or component 
part of the cell. 

The experiments of Boussingault on the growth of 
plants, in the absence of all nitrogenous food (' Annal. 
de Chim. et de Phys.,' ser. iii., xliii., p. 149), though 
undertaken for a different purpose, are well adapted to 
remove all doubt about the very impoi'tant power pos- 
sessed by the nitrogenous matter just now alluded to, 
viz. of maintaining the vital process in the plant, even 
where the mass of the plant itself receives no increase. 

In these experiments lupines, beans, oats, wheat, 
and cresses were sown in pure pumice-stone dust, washed 
and burnt, with which was mixed a certain quantity of 
ash from stable-manure and from seeds similar to those 
sown. The plants were grown partly under glass bells, 
wdth a constantly-renewed supply of air containing car- 
bonic acid. The air supplied and the water used for 



FUNCTION OF THE NITROGENOUS MATTEK OF SEEDS. 57 

the plants, were most carefully freed from ammonia. 
The results of these experiments were as follows : — In 
an experiment where the plants were grown under a 
glass bell, 4*780 grammes of seeds (lupines, beans, and 
cresses), containing 0'2iJ7 gramme of nitrogen, gave 
IG'G grammes of dried plants ; adding the amount of 
nitrogen in the soil, 0'224 gramme ot that element was 
recovered. In another experiment, where the plants 
were grown in free atmospheric air, with the exclusion, 
however, of dew and rain, 4*995 grammes of seeds (lu- 
pines, beans, oats, wheat, and cresses) gave 18*73 
grammes of dried plants. The seeds contained 0*2307 
gramme of nitrogen ; the plants and soil, 0*2499 
grannne. In the first scries of experiments all ele- 
ments of food were supplied to the plants, except nitro- 
gen ; the chief conditions required to form unazotised 
matter were given, but those required to form azotised 
matter were altogether excluded. 

The growth of a wheat plant in pure water and at- 
mospheric air is unattended with any increase of 
weight. The normal seed-com contains a certain quan- 
tit}^ of potash, magnesia, and lime, which are required 
internally for the organic formative process ; but it has 
no excess of those mineral substances that could serve 
to eft'ect the chemical process of a new production of 
protoplasm. Where the mineral substances are ex- 
cluded, the organs will absorb water, but neither car- 
bonic acid nor ammonia ; at all events, these two latter 
substances, even though they be introduced into the 
plant by means of the water, exert no influence upon 
the internal process ; they sufier no decomposition, and 
no vegetable matter is formed from their elements. 

In Boussingault's experiments, the action of the 
mineral substances supplied is unmistakable. The 
weight of the plants produced was nearly 3^ times 
greater than that of the seeds sown : but the quantity 
of nitrogenous matter was the same as in the seeds. 
Hence we have a clear production of non-nitrogenous 
substance 2-^ times more than the original weight of 
the seeds. A simple calculation shows that the nitro- 

8* 



58 THE PLANT. 

gen in the seed lias, under these circumstances, caused 
the generation of 56 times its own weight of unazotised 
matter ; or, what comes to the same thing (taking the 
amount of carbon in tlie latter at 44 per cent, only), the 
decomposition of 90 times its own weight of carbonic 
acid. 

The course of vegetation in these plants tln-ows 
sufficient light upon the processes going on in their or- 
ganism ; in the first days their developement was vig- 
ourous, afterwards languid. The first-formed leaves 
withered after a time, and partly dropped off, fresh 
leaves being developed in their stead, which went on in 
the same way ; and the vegetation seemed to reach a 
point where the newly developed parts existed at the 
expense of the decaying portions. A French bean, 
weighing 0'755 gramme, planted on the 10th May, had 
by the 30th July developed 17 leaves, of which the first 
11 w^ere then dead and gone. The plant flowered, and 
on the 22nd August, when nearly all the leaves had 
dropped off, produced a single small bean, which 
weighed 4 centigrammes, the -x^th. part of the weight 
of the seed-bean. The entire crop weighed 2*24 
grammes, very nearly three times as much as the seed- 
bean. In the case of a rye-plant it w^as very clearly 
observed how the unfolding of every fresh leaf was at- 
tended with the death of one of the old leaves. 

In the second series of experiments, the plants had 
absorbed (from the air) 1'92 milligramme of nitrogen, 
and produced 0.830 gramme more vegetable substance, 
giving 43 milligrammes of unazotised matter for every 
milligramme ot nitrogen. 

The difference in the developement of a plant in 
pure water from that of one grown, as in Boussingault's 
experiments, in a soil supplying the incombustible con- 
stituents of food, is clear and unequivocal. The organs 
first formed received in both cases their elements from 
the seed ; in both, a certain quantity of mineral sub- 
stances and also of soluble unazotised matter was con- 
sumed to form cellulose in the leaves, roots, and stems ; 
and the proportion of the unazotised to the nitrogenous 



DIFFERENCE IN DEVELOPKMENT. 69 

matter was altered. In the plant growing in water, 
there was a constant decrease of nnazotised matter ; 
while in the other a certain quantity of that substance 
was generated anew. Nothing can be more certain 
than that in Boussingault's experiments, the Urst-formed 
leaves acquired by tlie supply of mineral substances the 
faculty of absorbing and decomposing carbonic acid, a 
power not possessed by the plant developed in pure 
Avater ; and that as mucli soluble nnazotised substance 
was reproduced as had been consumed in the formation 
of the leaves and roots by the conversion into cellulose 
of the store originally present. 

In the movable constituents of the plant, the rela- 
tive proportion betAveen the nnazotised and the azotised 
seed constituents was manifestly restored pretty nearly 
as it existed in the seed ; both matters passed through 
the stem into every new-formed leaf-bud, and took part 
in the developement of new leaves, by whose operation 
the consumption of nnazotised matter was always made 
o:ood again within a certain limit, so that the same pro- 
cess could be repeated again and again for months. In 
every one of the dead leaves (and root fibres) a certain 
quantity of the azotised substance remained behind, and 
in the last period of vegetation the floating remainder 
of this substance was collected in the pod and in the 
seeds. 

The supply of mineral substances had served to 
effect the continuance of the chemical process, and 
caused the ])roduction of nnazotised substances. By 
the presence of these mineral bodies, and by the coop- 
eration of the azotised matters, new material was en- 
gendered from carbonic acid to form the cell-walls, and 
the term of life was prolonged to its proper limit. The 
most remarkable point is, that a quantity comparatively 
so small, of azotised substance derived from the seed, 
should so long be able to ])erform its assigned functions, 
apparently without suffering any alteration ; so that in 
the body of the living plant, made to ])roduce and col- 
lect it, it would seeni^ to possess a kind of indestructi- 
bility. 



60 THE PLANT. 

If we consider, that, in the cited experiment with 
the French bean, a great part of the additional unazo- 
tised substances which wei'e ])roduced fell away in the 
dying leaves from the body of the plant, it will be seen 
that the supply of mineral substances was of no use to 
the bean-plant in the absence of nitrogenous food. 

Lastly, it is quite intelligible that the amount of 
azotised matter contained in a bean might perhaps suf- 
fice to sustain for years the vegetation of one of the 
conifers with persistent leaves, and to produce many 
hundred — perhaps many thousand — times its own 
weight of woody substance ; and that such a plant 
upon a barren soil altogether unsuited for other plants, 
might thrive with a very sparing su[)ply of nitrogenous 
food, if the soil contained a j^roper store of those min- 
eral substances which are indispensable for the genera- 
tion of un azotised matter. 

The growth of a plant essentially consists in the en- 
largement and multiplication of the organs of nutrition, 
i. e. the leaves and roots. The enlargement of the first, 
or the production of a second leaf or root fibre, requires 
the same conditions as the production of the first. The 
analysis of the seeds teaches us with tolerable certainty 
what these conditions are. In the normal conditions of 
nutrition, the first roots and leaves, whose elements were 
supplied by the seed, produce from certain mineral sub- 
stances organic com]iounds, which become i)arts and 
constituents of themselves, or constituents of fresh leaves 
and roots, consisting of the same elements and having 
the identical properties of the first, i. e. they possess the 
same power to transform inorganic nutritive substances 
into organic formative materials. 

It is quite clear that the enlargement of the first 
leaves and roots and the production of new ones, must 
have required azotised and unazotised substances in the 
same proportioif as in the seed, which makes it j^robable 
that the organic operations of the plant under the do- 
minion of sunlight uniformly ])roduce in all periods of 
growth the same materials, i. e. the constituent ele- 
ments of the seed, vdiich serve to build up the plant, 



FUNCTION OF AZOTISED MATTER IN PERENNIALS. 61 

beinfij formed into leaves, stems, and root-fibres, or 
finally into seed. The soluble constituents of a bud, a 
tuber, or the root of a perennial plant, are identical 
with the seed constituents. The cereal plant produces 
azotised and unazotised substances in the same propor- 
tion as in the albumen (farinaceous body). The potato 
plant produces the constituents of tlie tuber, which are 
formed into leaves and branches or roots ; or, if the ex- 
ternal conditions are no longer favourable to the forma- 
tion of leaves and roots, accumulate again in the under- 
ground stem, to form new tubers.* 

While the growth of the plant continues, the first as 
well as the last leaves and roots will, with a proper 
supply of food, maintain their existence, since they re- 
produce out of the nutriment supplied to them the 
identical constituents from which they themselves arose. 
The excess of these, which they do not require for their 
own enlargement, goes to those parts of the plant where 
the motion of the fluids or the cell-formation is most 
active, — viz., to the roots, the leaf-buds, or the extreme 
points of the roots and shoots ; and, finally, as in the 
case of summer plants, to the organs of seed-formation 
which at the ripening of the seed absorb most of the 
movable seed-constituents existing in the plant. 

The supply of the incombustible elements of food 
led to the formation of unazotised matter, a portion of 
which was used to form woody tissue, whilst another por- 
tion remained available for the same purpose. Tlie supply 
of nitrogenous food caused a corresponding production 
of nitrogenous matter, so that the protoplasm was con- 
stantly renewed, and, so long as the chemical process 
lasted, was increased. 

* Boussingault has observed that even seeds weighing two or three 
milligrammes, sown in an ahsohitcly sterile soil, will produce plants in 
which all the organs are developed, but their weight, after months, docs 
not amount to much more than that of the original seed, even if they 
vegetate in the open air ; and the result is more marked if they grow in a 
confined atmosphere. The plants remain delicate, and appear reduced in 
all dimensions ; they may, however, grow, flower, and even bear seed 
which only requires a fertile soil to produce again a plant of the natural 
size. (' Compt. rend.' t. xliv. p. 940.) 



62 THE PLANT. 

To enable a plant to flower and bear seed, it would 
appear necessary in the case of many plants tliat the 
activity of the leaves and roots should reach a period of 
rest. It is only after this that the process of cell-forma- 
tion seems to gain the ascendancy in a new direction ; 
and the constructive materials being no longer required 
for the formation of new leaves and roots, arc used to 
form the flower and the seed. In many plants the 
want of rain, and the consequent deficiency of incombus- 
tible nutritive substances, will restrain the formation of 
leaves and hasten the flowering. Dry, cool weather 
favours the production of seed. In warm and moist 
climates the cereals sown in summer bear little or no 
seed ; and on a soil poor in ammonia the root-plants 
more readily flower and bear seed than on a soil rich in 
that substance. 

If the normal processes of vegetation require a defi- 
nite proportion of unazotised and azotised materials in 
the protoplasm which is formed in the plant, it is evi- 
dent that the want or excess of the mineral substances 
indispensable for the production of those matters must 
exercise a very decided influence upon the growth of 
the plant, and upon tlie formation of the leaves, roots, 
and seed. Want of azotised and excess of fixed nutri- 
tive substances would lead to the formation of unazo- 
tised materials in preponderating quantity ; but when 
these have assumed the form of leaves and roots, they 
retain a certain amount of nitrogenous matter, thereby 
impairing the seed formation, a principal condition of 
which is an excess of protoplasm. An excess of azotised 
food, with a deficiency of fixed nutritive substances, will 
be of no use to the plant itself, because tlie latter can 
for its organic operations make use of nitrogenous sub- 
stances only in proportion as they exist in the proto- 
plasm, and the contents of the cell are of no value to 
the plant in the absence of the materials required to 
form the cell-walls. 

In the process of animal life the organs of the body 
are constructed from the elements of the egg ; the con- 
stituent parts of such constructed organs are azotised, 



ABSORPTION BY THE ROOTS OF PLANTS NOT OSMOTFC. 63 

wliereas in the i)lant they contain no nitrogen. All 
processes of vegetative life tend simply to produce the 
elements of the seed. The plant only lives in generat- 
ing the egg-constituents and the egg itself ; the animal 
only lives by destroying these very egg-constituents. 

On one and the same soil equally suited for the tur- 
nip and the wlicat-jtlant, the former ])roduces for the 
same amount of azotiscd snbstance twice as much un- 
azotised matter as the latter. It is manifest that if two 
plants produce within the same time different quanti- 
ties of hydrates of carbon (wood, sugar, and amylum), 
the organs of decomposition must be arranged in a man- 
ner not only to afford adequate room for the carbonic 
acid supplying the carbon, and for the water su])plying 
the hydrogen, as well as to ]-)resent a suitable extent of 
surface to the action of the light, but also to permit the 
liberated oxygen to escajie as promptly as it becomes 
free. If we compare in this respect the leaves of a 
wheat-plant with those of a turnip-plant, we find a 
striking difference in their size, and in the amount of 
water respectively contained in them ; and a microscopic 
examination reveals still greater differences. Thewdieat- 
plant has erect leaves, which present to the light a 
much smaller surface than the leaves of the turnip- 
plant, which overshadow the ground, preventing the 
drying of the soil and the exhalation from it of carbonic 
acid. In the wheat-leaf the stomates are equally tliick 
on both sides ; in the turnip-leaf they are much more 
numerous, although smaller than in the wdieat-leaf, and 
a for greater number of them are found on the lower 
than on the upper side. 

All the facts known respecting the nutrition of 
plants tend to prove that it is not by a mere osmotic 
process that they absorb their food, but that the roots 
perform a very definite active part in selecting from the 
amount of food presented to tliem sucli matters and in 
such quantities as are best suited to tlie plant. 

The infiuence of the roots is most manifest in the 
vegetation of marine and fresh-water plants, whose roots 
are not in contact with the soil. 



64: 



THE PLANT. 



These plants received their incombustible nutritive 
substances from a solution in which these elements are 
most uniformly mixed and ditiiised ; and yet a com- 
parative analysis of the water and the ash-constituents 
of these plants shows that each species absorbs from the 
same solution different cjuantities of potash, lime, silicic 
acid, and phosphoric acid. 

The ash of duckweed was found to contain 22 parts 
of potash to 10 parts of chloride of sodium, whereas the 
water in which the plant had grown contained only 4 
parts of potash to 10 parts of chloride of sodium. In 
the plant the relative proportion of the sulphuric acid 
to the phosphoric acid was 10 to 14 ; in the water, 10 
to 3. 

It is quite the same with marine plants. Sea-water 
contains for 25 or 20 .parts of chloride of sodium 1'21 to 
1'35 of chloride of potassium ; but the plants growing 
in it contain more ])otash than soda. The kelp of the 
Orkney Islands, which consists of the ashes of many 
species of fucus,* contains for 26 per cent, of chloride 
of potassium only 19 per cent, of chloride of sodium. 

Sea-water contains manganese, but in such exceed- 
ingly small quantity that it would certainly have 
escaped analysis, were it not invariably found among 
the ash-constituents of many marine plants. The ash 
of Padhia pavonia (a species of tang) is found to con- 
tain of this mineral even more than 8 per cent, of the 
weight of the dried plant.f 

By the same power of selection the laminaria with- 
draw from the sea-water in which they grow the iodine 
compounds present in it in such exceedingly minute 
quantities. Chloride of potassium and chloride of sodi- 
um have the same form of crystallisation, and so many 

* See Godechen's analysis of the ash of different species of fucus. 
(' Annal. d. Chcm. i:nd Pharm.' liv. 351.) 

f To give some idea of the extraordinary power which this phint must 
possess to witlidraw the manganese from sea-water, I need simply state 
that the quantity of this metal in sea-water is so exceedingly small, that I 
could find distinct traces of it only by subjecting the sesquioxide of iron, 
obtained from twenty pounds of sea-water, to a most searching analysis. 
(Forchhammer and Poggendorff, xcv. p. 84.) 



OSMOSIS AND ABSOKPTION BY ROOTS. 65 

other properties in common, tliat withont the aid of 
chemical means we cannot accurately distinguish the one 
from the other. But tlie plant clearly tliscriminates 
between the two salts, for it sei)arates the one from the 
other, and for every one equivalent of potassium Mhich 
it absorbs leaves behind in the water more than thirty 
equivalents of sodium. Manganese and iron, iodine 
and chlorine, are likewise isomorphous bodies ; yet the 
iodine plant separates one equivalent of iodine in sea- 
water from majiy thousand equivalents of chlorine. 

Tlie known laws of osmosis, and of the diffusion or 
interchange of water and salts through a dead mem- 
brane or a porous mineral body, give no ex])lanation 
whatever of the action exercised by a living membrane 
upon salts in solution, or liow' they pass through it into 
the plant. The observations of Graham (' Phil. Mag.' 
ser. IV. August 1850) show that matters capable of 
exerting a chemical action upon animal membranes, 
such as carbonate of potash and caustic jiotash, causing 
them to swell and gradually decomposing them, facili- 
tate the passage of water to an extraordinary degree.* 
Graham remarks that the processes of alteration, decom- 
position, and new formation, which are incessantly 
taking place in the membranes and cells in all parts of 
the plant, and which we have no means of defining or 
measuring, must entirely change the osmotic process : 
the permeation of mineral substances through the living 
vegetable membrane must, therefore, be governed by 
very complex laws. 

Land plants act in the same manner with respect to 
the soil in which they grow, as marine plants to sea- 

* The water in the tubes of his osmometer rose to IfiV millimeters, 
when holdinj: 1 lOw. per cent, of carbonate of potash in solution; with 1 
per cent, of that salt, it rose to 8G3 millimeters (38 inches, Enf^lish). In 
another experiment, the water holding 1 per cent, of sulphate of potash in 
solution, rose to twelve millimeters ; upon tlie addition of 1/10 percent, of 
carbonate of pota.'^h to the solution, it rose to 254-264 millimeters ; the 
same potash solution by it.self rose only to 92 millimeters. The notion of 
an osmotic equivalent is altogether inadmissiijle, if the membrane is 
chemically altered. Graham's latest investigations on the dialysis of 
crystalline and amorphous bodies are extremely interesting, and promise to 
throw considerable light upon the processes in the animal organism. 



66 THE PLANT. 

water. One and the same field presents to the plants 
growing in it, the alkalis, alkalme earths, phosphoric 
acid, and ammonia, in absolutely the same form and 
condition ; but the ash of no one species of plant ever 
shows the same relative proportions of component ele- 
ments as the ash of another species. Even the parasit- 
ical plants, which draw their mineral constituents in a 
certain state of preparation, from other plants on which 
they live, as the mistletoe ( Yisciirn aVniTn), do not com- 
port themselves to the latter as a graftling to a tree, but 
absorb from the sap very difterent proportions of min- 
eral constituents (' Annal d. Chem. und Pharm." liv. 
363). ISTow, as the soil is perfectly passive in respect to 
the supply of these materials, there must be some 
agency at work in the plant itself, which regulates the 
absorption according to the requirements of each plant. 

The observations made by Hales (see Appendix C.) 
show that the exhalation from the surface of the leaves 
and branches exercises a powerful influence upon the 
motion of the fluids, and upon the absorption of water 
from the soil. If the plant drew its mineral food from 
a solution moving about in the soil and passing imme- 
diately into the roots, then two plants of dlfiferent spe- 
cies or kind, placed in the same conditions, would re- 
ceive the same mineral substances in the same relative 
proj)ortions ; but, as we have seen, two plants belonging 
each to a different species contain these substances in 
the most dissimilar proportions. 

That a selection takes place in the absorption of food 
by the roots is a fact beyond dispute. 

In the case of aquatic plants, which grow under 
water, exhalation is altogether excluded as a possible 
operating cause of the passing of the food into the body 
of the plant. In these plants the absorbent surface 
must exercise very unequal powers of attraction upon 
the different materials, which arc presented by the solu- 
tion in the same form and in a state of equal mobility ; 
or, what comes to the same thing, the resistance offered 
to their passage through the outermost cellular layers 
must be very dissimilar. The case cannot be different 



POWKK OF SELECTION BY ROOTS NOT ABSOLUTE. 67 

with the roots of land-plants, to judge from the unequal 
proportions of the substances severally absorbed by 
them. 

The power of the roots to preclude the passing of 
certain substances from the soil into the plant is not 
absolute. ForchJiammer (Poggend. ' Annal.' xcv. 90) 
detected exceedingly minute traces of lead, zinc and 
copper in the wood of the beech, birch, and fir ; and 
tin, lead, zinc, and cobalt in that of the oak ; but the 
fact that the outer rind or bark, in particular, is found 
to contain metals of this kind in perceptibly larger 
quantities than the wood, clearly points to the acci- 
dental nature of their presence, and to their taking no 
essential part in the vital processes of the plant. 

How snuxll the quantities of these metals must be 
which the roots of these trees absorb may be judged 
from the fact that hitherto chemical analysis has not 
been able to detect traces of any other metal than man- 
ganese and iron, in the water of wells, brooks, or 
springs ; and their appearance in these wood-plants, 
which during the growth of half a century or more have 
absorbed and evaporated an immense quantity of water, 
is the only proof we possess, that this water must actu- 
ally have contained these metals in some form or other. 

The observations of De Saussuee, Schlossbergee, 
and IIeeth, show that the roots of laud and water 
plants absorb from very dilute saline solutions water 
and salt in proportions entirely different from those in 
the fluid ; in all cases a greater proportion of water, and 
a less quantity of salt. In plants watered with very 
dilute solutions of salts of baryta, Daubeny found no 
baryta, whereas Ivnop in similar experiments detected 
this substance. The general result of all these experi- 
ments is that, of themselves, the plants have not the 
power of offering a permanent resistance to the chem- 
ical action of salts and other inorganic compounds upon 
the exceedingly fine membrane of the root. 

Most land-plants in their natural state in the soil 
can bear no salt solutions, as concentrated as in these 
experiments, without sickening and dying ; and even 



68 THE PLANT. 

carbonate of potasli and ammonia, whicli we certainly 
know to be nutritive substances, act upon many plants 
as poison, even when present in the water which circu- 
lates in the ground only in sufficient quantity to impart 
a blue tint to red litmus paper. On the other hand, it 
would be very wonderful if the roots of a plant outside 
the soil, and in conditions not suitable to their nature 
should, under the influence of evaporation, be impene- 
trable for salt solutions.* 

Those mineral substances which, like iron, are con- 
stant constituents of all plants, though present only in 
very small proportions, must be regarded very different- 
ly from those metals which Forchhammer found in 
woody plants. 

We know the part which iron performs in the ani- 
mal organism, in which it is present in comparatively 
no larger quantities than in the seeds of cereals ; and 
we are fully convinced that, without a certain amount 
of iron in the food of animals, the formation of the 
blood corpuscles, the agents of one of the chief func- 
tions of the blood, is impossible. Hence, by the law 
of dependence, which links together the life of animals 
and plants, we are compelled to ascribe to the iron in 
the plant also an active part in its vital functions so 
material that the absence of that metal would endanger 
the very existence of the plant. 

Hitherto chemistry has attributed a positive part in 
the vital process of plants to those incombustible sub- 
stances only which are common to all, and which differ 
only in the relative proportions in the plants. But 

* If the long limb of a syphon-shaped tube, filled with water and closed 
■with thick pieces of pig or ox bladder tied over both openings, is placed in 
salt-water or oil, and the other limb is exposed to the air, the water 
evaporates in the pores of the bladder with which the short limb is closed. 
By the capillary action of the bladder, the water exuding in gaseous form 
is taken up again on the other side of the bladder, and a vacuum is thus 
created in the interior of the tube, whence there is an increased pressure 
upon the surfaces of both bladders, which forces the salt-water or the oil 
through the bladder into the tube. (' Researches into some of the Causes 
of the Motion of Fluids, by J. v. Liebig. Brunswick : Fr. Viewig & Son. 
1848.' — p. 6*7.) A plant in similar conditions is just like a tube closed 
with penetrable porous membranes. 



IKON AXD ZINC NECESSARY FOE PLANTS. 09 

should the conjecture prove true that iron is a constant 
constituent of chlorophyll and of the leaves of many 
flowers, it may be assumed that other metals, found in- 
variably present in certain varieties of plants (as man- 
ganese in Pavonia, Zosiera, TrcqM naians^ in many 
ligneous plants, several cereals, and in the tea shrub), 
take part in the vital functions, and that certain pecu- 
liarities depend upon the presence of those metals. The 
ash oi Viola calaininarla^ a plant which, in the parts 
about Aix-la-Chapelle, is held so strongly indicative of 
the presence of zinc, that the places where it grows are 
selected for opening new mines in search of zinc ore, is 
found to contain oxide of zinc. (Alex. Braun.) 

As chloride of sodium and chloride of potassinm 
cause some plants to thrive, so iodide of potassium 
manifestly performs a similar part in others ; and if 
one plant may properly be called a chlorine plant, 
others may with ecpial propriety be termed iodine 
plants, or manganese plants.* (Prince Salm-Horst- 
mar.) 

The diversity in the amount of iodine in different 
varieties of fucus {Gocdechens), or of alumina in various 
kinds of Lycoj>odium (Count Laubach), remains, indeed, 
unexplained ; but the power of plants to withdraw sub- 
stances like iodine, even in the smallest quantities, from 
the sea water in which they grow, and to accumulate 
and retain them in their organism, can only be ex- 
plained upon the assumption that these substances have 
entered into combination with certain constituent parts 
of the plants, whereby as long as the plant lives they 
are prevented from returning to the medium from 
which they were taken.f 

* Tlie examination of tlie following water-plants revealed the presence 
of considerable quantities of manganese and iron in their ash, though the 
water in which they grew apparent!}- contained no trace of manganese : — 
Victoria reffia {m tlie leaf-stalk principally manganese, in the leaf iron) ; 
Nipnphica cwrulea, diutata, luiea ; Ilydrocliuris Jlumboldli ; Xeluiiibium 
asperifolium. (Dr. Zuller.) 

f With respect to the copper in the grains of wheat and rye, which 
Meier of Copenhagen has shown to be a constant constituent of both seeds, 
Forchhammer (PoggendorfTs ' Annal.' xc. 92) remarks : — ' It is an old and 



70 THE PLANT. 

It might be supposed that plants become saturated 
witli tlie substances absorbed from the air and from the 
soil ; and that all materials offered by the soil in solu- 
tion, or made soluble by the cooperation of the roots, 
are absorbed without distinction. Upon this assump- 
tion, only that substance in the plant could of course 
pass into it from without, which is withdrawn from the 
solution within for a formative purpose. 

The investigations made by Schultz-Fleeth show 
that NymphcBa alba and Arundo jpliragmites absorb 
from the same soil and water, the former nearly 13 per 
cent., the latter 4*7 per cent., of ash constituents ; and 
of these silicic acid in the most unequal proportion ; 
the ash of NyTnphma alba containing less than -J per 
cent, of that substance, while in the ash of Arundo 
phragmites there ai-e above 71 per cent. Upon the 
supposition just made, an equal amount of silicic acid is 
offered to the roots of both plants, and" they both take 
up an equal quantity of it in proportion to the volume 
of the sap respectively. In the reed plant the silicic 
acid is incessantly withdrawn from the sap, and depos- 
ited in a solid state in the leaves, the margins of the 
leaves, the sheaths, &c. As the sap within contains 
less silicic acid than the solution without, fresh quanti- 
ties of it are absorbed from the latter ; but not so with 
the Nxjmplima^ because the silicic acid taken rip by that 
plant is not consumed in it. 

If we accept the same reasons for the passage into 
the plant of carbonic acid and phosphoric acid, then it 
can possess no actual power of selection, but the per- 
meation of the nutritive substances will depend upon 
osmotic conditions. 

It certainly cannot be denied that the absoi-ption of 
nutritive substances depends upon growth or increase 

approved practice to steep grains of wheat, intended for sowing, in a solu- 
tion of sulpliate of copper. The usual explanation of this practice is, that 
sulphate of copper destroys the sporules of blight to which the wheat plant 
is liable, an explanation which it is not my intention to dispute. Still it 
might also be held, supposing copper to be an essential constituent of 
wheat, that the practice in question serves to supply the copper necessary 
for the vigorous growth of the plant.' 



PASSAGE OF MATTERS INTO THE ROOTS. 71 

in mass ; for as it is certain tliat a plant will not grow 
it" no food id offered to it, so it is equally certain that it 
will absorb no nutriment if the external conditions are 
not favourable to growth. Yet the view given above 
"would force us to conclusions which are not founded in 
nature ; such as, for instance, (1) that there is actually 
around the roots a solution containing all the ash con- 
stituents of the plants ; and (2) that the roots of all 
plants have a similar structure, and their sap is of the 
same nature. 

With regard to the roots, tho most common observa- 
tions appear to show that they possess the power of 
selecting the proper mineral nutriment for the plant 
from the matters presented to them. All plants do not 
thrive equally well in the same soil ; one kind succeeds 
best in soft water, another in hard water, or water 
abounding in lime ; another only on marshy ground ; 
many on fields rich in carbon and carbonic acid, such 
as the turf-plants ; others again on soil containing large 
quantities of alkaline earths. Many mosses and lichens 
will grow only on stones, the surfaces of which they 
sensibly change ; others, like Kulcria^ possess the faculty 
of extracting from silicious sandstone potash and the 
phosphoric acid so sparingly present in it. Roots of 
grass attack the felspar rocks, accelerating their disin- 
tegration. Rapes and turnips, sanfoin and lucerne, as 
also the oak and beech, receive the chief part of their 
food from the subsoil poor in humus ; wdiile the cereal 
and tuberous plants thrive best in the arable surface 
soil, and in soil abounding in humus. Tlie roots of 
many parasitic plants are absolutely unable to extract 
from the soil their necessary food ; but this is prepared 
for them by the roots of the plants on which they grow. 
Others again, as certain fungi, grow only on vegetable 
and animal remains, whose azotised and unazotised sub- 
stances they use for their own construction. 

These tacts, accepted in their true significance, seem 
sufficient to remove all doubt respecting the different 
action of the roots of plants upon the soil. We know 
that common Lycopodhiin (club-moss) and ferns absorb 



Y2 THE PLANT. 

alumina ; yet we also know that this substance, in the 
form in which it occurs in all feilile soils, is not soluble 
in pure water, or water containing carbonic acid ; and 
that it cannot be detected in any other plant growing 
on the same soil by the side of the club-moss. In like 
manner, Schultz-Fleeth could not discover in the water 
in which Arunclo phragmites (one of the plants most 
abounding in silicic acid) was growing, sufficient silicic 
acid to yield a ponderable amount in the composition 
of 1000 parts of the water. 



CHAPTER II. 



THE SOIL. 

The ^i1 contains the food of plnnls — Soil and subsoil . conversion of the latter into 
the former— Power of the soil lo withdraw tho food of plants from solution in 
pure and in carbonic acid water ; similar action of charcoal ; process of surface 
attraction ; chemical decomposition often accompanies this attraction of the 
food of i)lants in the soil , general resemblauco of the t^oil in its action to ani- 
mal charcoal— All arable 8i>ils posse-s the jjower of absorption, but in different 
decrees— Mode of the distribution of the food of plants in the soil ; chemically 
and physically fixed condition of the food— Only the physically lixed are avail- 
able to plants", bein^ made soluble by the roots— Power of the soil to nourish 
plants; on what dependent— Comportment of an exhausted soil In fallow — 
Means for making the chemically (ixed eUmeits of fo.nl available to plants— 
Action of air, weather, decaying ors^anic mailers and chemical means — Distri- 
bution of phosphoric and silicic acids ; influence of ortranic matters— Action of 
lime- Process of the absorption of food from the soil by the extremities of the 
roots— Mechanical preparation of tho soil ; its iiifluenee o;i the growth of 
plants ; chemical means for preparing the soil— Rotation of crops; its influ- 
ence on the quality of the soil ; action of drainin-i — Plants do not receive tlieir 
food from a solution circulating in the soil ; examination of drain ; lysenietcr, 
spring and river water ; bog water, food of plants contained in it ; Bid keiiancr 
spring water contains volatile fattj' acids . amount of food of p'ants in natural 
waters dependent on the nature of the soil ihrough whiih tl.ey flow— Mud and 
bog earth as maiitiie ; explanation of their action — Manner in which jilants 
take up their food from the soil ; experiments on the growth of plants in solu- 
tions containing their foo 1 ; similar experiments with soil containing the food 
in a physically fixed state — Intimate connection of natural laws — Average 
crop ; necessary quantity of assimilable food in tho soil for the production of 
such ; importance of the extent of surface of the food in the soil ; the root sur- 
face—Quantity of food for a given surface of roots necessary for a wheat or 
rye crop — Analysis of the soil of a field— Difterenoe between fertility and pro- 
ductive power of a field — Mode of estimating relative extent of root surfaces 
— Conversion of rye into wheat soil ; quantity of food necessary for the pur- 
posi' ; the plan impracticable — Immobility in tlie soil of the food of plants ; ex- 
perience ill agriculture— Ueal and ideal maximum production- Convers.oii in 
practice of the chemically lixed food into an available form — Eft'ect of amniuiro 
depends upoi the property of the sod — Improjier relative iiroportions of tho 
ditVerent elements of food in the so I ■ efl'ect of this upon the different culti- 
vated plants : means for restoring the proper relative proportions. 

I^ROM the soil plants receive the food necessary for 
- tlieir developement ; hence an acquaintance with its 
chemical and pliysical properties is important in helping 
us to understand the nutritive processes of plants, and 
the operations of agriculture. As a matter of course, a 

4 



74 THE SOIL. 

soil to be fertile for cultivated plants, must, as a pri- 
mary condition, contain in snfiicient quantity the nutri- 
tive substances required by those plants. But chem- 
ical analysis, whicli determines this relation, gives but 
rarely a correct standard by which to measure the 
fertility of difierent soils, because the nutritive sub- 
stances therein contained, to be really available and 
effective, must have a certain form and condition, which 
analysis reveals but imperfectly. 

Rough uncultivated ground, and soil formed from 
the dust and dried mud of the highroads, are speedily 
overgrown with weeds, and though often still unfit for 
the cultivation of cereal and kitchen plants, may, yet 
prove not unfruitful for other plants, requiring, like 
clover, sanfoin, and lucerne, a large amount of food, 
and which are often seen thriving luxuriantly on the 
slopes of railway embankments formed of earth that 
has never been imder cultivation. A similar relation is 
shown by the subsoil of many fields. In many of them 
the earth from the deeper layers improves the surface 
soil, and increases its fertility ; in others, the subsoil 
mixed with the surface soil destroys the fertility of the 
latter. 

It is a remarkable fact that rough uncultivated soil, 
unsuited for cereal and kitchen plants, may by diligent 
cultivation during several years, and by the influence 
of the weather, become fertile enough to produce those 
plants which it formerly refused to bear. The dif- 
ference between fertile arable land and barren untilled 
soil is not the result of any dissimilarity in the nutritive 
substances which they contain ; because in cultivation 
upon a large scale, to convert the untilled i-ough soil 
into fertile arable land, the ground, so far from being 
enriched, is rather impoverished by the cultivation of 
other plants on it. 

Tlie difference between the subsoil and the arable 
surface soil, or the crude and the cultivated soil, sup- 
posing that both contain the same amount of nutritive 
substances, can only be founded upon this, that the cul- 
tivated ground contains the nutritive substances of 



A SOIL WHEN SAID TO BE FERTILE. TS 

plants, not only in a more uniform mixture, but also in 
another form. 

Now as from the influence of cultivation and wcatlicr 
above-mentioned, the r()ni2;h soil acquires tlie power of 
furnisliing the elements of food which it contains, in just 
the same quantity and in the same time as cultivated 
soil, a power which was formerly wanting in it with 
regard to certain plants, it cannot be denied that an 
alteration must have taken place in the original form 
and fashion of these elements. 

Suppose we have a soil consisting of disintegrated 
rocks : in the smallest particles of such a soil, the nutri- 
tiv(i substances of plants, as potash for instance in a 
silicate, are retained in combination by the chemical 
attraction of silicic acid, alumina, &c. This attraction 
Las to be overcome by one still more powerful, if the 
potash is to be liberated and made available for passing 
into plants. If we find that some plants are perfectly 
de /eloped in a soil of the kind, which remains unfruit- 
ful for others, we are led to assume that the former are 
able to overcome the chemical resistances opposed to 
their growth, and that the latter are not. Further, if 
we find the same soil gradually acquiring the power of 
producing these latter plants also, we can assign no 
other reason than this, that by the combined action of 
air, water, and carbonic acid, aided by mechanical 
operations, the chemical resistances have been over- 
come, and tlie alimentary substances have been reduced 
to a form in which they are available for absorption 
even by plants endowed witb the feeblest powers of 
vegetation. 

A soil can only then be said to be perfectly fertile 
for a given species of plant, e.g. wheat, when every part 
of its horizontal section Avliicb is in contact with the 
roots contains the amount of food required by the plant, 
in a form allowing the roots to absorb such food at the 
proper time, and in the proper quantity, during every 
stage of its developement. n 

In a former section mention has been made of a 
property possessed by arable soil, viz. that when 



76 THE SOIL. 

brought into contact -with solutions of the articles of 
food most essential for plants in pure water or in water 
containing carbonic acid, it can withdraw these ele- 
ments of food from such solutions. This power throws 
light upon the form and (condition in which these mate- 
rials are contained or combined in the soil. 

To estimate this j^roperty correctly in its bearing 
upon the life plants, we must call to mind a similar 
property in charcoal, which, like arable soil, withdraws 
from many tluids colouring matters, salts and gases. 

Tliis power in charcoal depends upon a chemical 
attraction proceeding from its surface, and the materials 
withdrawn from the fluid adhere to the charcoal in 
exactly the same way that the colouring matter adheres 
to the fibre of coloured stufi's coated over with it. 

The property of decolorising coloured fluids, which 
animal wood and vegetable fibre share in common with 
charcoal, is perceptible in those kinds of charcoal only 
which possess a certain degree of porosity. 

Powdered pit coal, and the shining, smooth, blis- 
tered charcoal from sugar or blood, have hardly any 
decolorising action ; whereas porous blood-cliarcoal and 
bone-charcoal with its fine pores exceed all other varie- 
ties in this property. 

Among the wood-charcoals, those made from poplar 
or pine, having wide pores, are inferior to the charcoal 
of the beech and box tree ; all these varieties decolorise 
in proportion to the extent of surface which attracts 
colouring matter. Tlie attractive force which charcoal 
exei'cises upon colouring matter is about on a par with 
the feeble atfinity of water for salts, which are dissolved 
by it, but without alteration of their chemical proper- 
ties. "When dissolved in water, a salt simply assumes 
the fluid state, and its particles acquire mobility ; but 
in all other respects it retains its characteristic propei*- 
ties, which, as is well known, are completely destroyed 
by the action of a stronger affinity than that of water. 

In this respect the attraction of charcoal resembles 
that of water, for both attract the dissolved matter. If 
the attraction of the charcoal is somewhat greater than 



ABSORPTIVE rOWEK OF SOILS. «7 

that of the water, then tlie colouring matter is com- 
pletely withdrawn from tlie water ; if the attraction of 
both is equal, a division takes place, and the attraction 
is only partial. 

The materials attracted by the charcoal retain all 
their chemical properties, and continue unaltered, mere- 
ly losing" their solubility in water ; yet very slight cir- 
cumstances, increasing in the least degree the attractive 
force of the water, are sufficient again to withdraw from 
the charcoal the materials absorbed by it, and which 
sim]>ly coat its surface. By a slight addition of alkali 
to the water the colouring matter may be discharged 
from the charcoal which has been used to decolorise the 
fluid, and by treatment with alcohol, the quinine or 
strychnine absorbed by charcoal from a fluid may be 
again extracted. 

The arable soil possesses, in these respects, the same 
properties as charcoals. Diluted liquid manure, of deep 
brown colour and strong smell, filtered through arable 
soil, flows off colourless and inodorous ; and not merely 
does it lose its smell and colour, but the ammonia, 
potash, and phosphoric acid which it holds in solution, 
are also more or less completely withdrawn from it by 
the soil, and this in a far greater degree than by char- 
coal. The rocks which by disintegration give rise to 
arable soil, if reduced to a fine powder, are just as little 
possessed of this power as pounded coal. On the con- 
trary, contact with pure water or water containing car- 
bonic acid, deprives many silicates of potash, soda, and 
other constituents, a clear proof that the former cannot 
possibly withdraw the latter from the water. There is 
no perceptible connection between the composition of a 
soil and its power of absorbing potash, ammonia, and 
]fliosphoric acid. A soil abounding in clay, with a 
small projiortion of lime in it, possesses this absorptive 
power in the same degree as a lime soil with a small 
admixture of clay ; but the amount of humus substances 
will alter the absorptive relation. 

By a closer observation we perceive that the absorp- 
tive power of arable soil differs in proportion to its 



T3 THE SOIL. 

greater or less porosity ; a dense, heavy clay soil and a 
loose sandy soil possess the absorptive power in the 
smallest degree. 

There can be no doubt that all the component parts 
of arable soil have a share in these properties, but only 
when they possess a certain mechanical condition, like 
wood or animal charcoal ; and that this power of 
absori3tion depends, as in charcoal, npon a surface 
attraction, which is termed a physical attraction, be- 
cause the attracted particles enter into no chemical 
combination, but retain their chemical properties.* 

The arable soil owes its formation to the disintegra- 
tion of minerals and rocks, brought about by the action 
of mighty mechanical and chemical agencies. Though 
the comparison may not be altogether apt, the rock 
may be said to stand in about the same relation to the 
arable soil resulting from its disintegration as the wood 
or the vegetable fibre to the humus resulting from its 
decay. 

The same causes which in the course of a few years 
convert wood into humus act also upon rocks, with this 
difierence, however, that it requires the combined action 
of water, oxygen, and carbonic acid, for probably a 
thousand years, to produce from basalt, trachyte, fel- 
spar, or porphyry, the thinnest layer of arable soil (such 
as is found in the plains of river valleys and low lands) 
with all the chemical and physical properties suited for 
the nutrition of plants. Sawdust possesses the proper- 
ties of humus no more than powdered rocks have the 
properties of arable soil. I^o doubt sawdust may pass 
into humus and powdered stones into arable soil, but 
the two states are essentially distinct ; and no human 
art can imitate the operations which were necessary, 
during immense ages, to convert the divers kinds of 
rocks into arable soil. 

Arable soil, resulting from the disintegration of 
various kinds of rocks, bears the same relation, in 

* The term, ' physical attraction,' as used here, does not signify a 
peculiar attractive force, but merely designates the ordinary chemical 
affinity, which shows differences of degree in its manifestation. 



ARABLE SOIL COMPARED TO ANIMAL CHARCOAL. Y9 

respect of absorptive power for inor'ganic substances in 
solution, as the woody fibre altered by the action of 
heat bears to organic substances in solution. 

It has been stated, that from a solution of carbonate 
of potash or ammonia, or from a solution of pliosphate 
of lime in carbonic acid water, the arable soil will with- 
draw the potash, ammonia, and phosphoric acid, with- 
out any chemical interchange with the constituents of 
tlie earth taking place. In this respect the action of 
arable soil is absolutely like that of charcoal. But it 
goes farther, for it is sufficiently powerful to sever the 
connection between the potash or ammonia and the 
mineral acid, for which they have the greatest affinity, 
the potash being absorbed by the soil just as though it 
were not combined with an acid. 

In this property arable soil is like animal charcoal, 
which, by means of the phosphates of the alkaline earths 
contained in it, decomposes many salts that are not 
affected by charcoals free from such phosphates ; and, 
without doubt, the lime and magnesia compounds in- 
variably present in arable soil have a share in this de- 
composing power which it possesses. 

We must suppose that the attractive force of the 
earthy particles would not in itself be strong enough to 
separate, for instance, potash from nitric acid, and that 
it requires the additional attraction of the lime or mag- 
nesia to decompose the nitrate of potash. On the one 
side the soil attracts the potash, on the other the lime 
or magnesia in the earth attracts the nitric acid, and 
thus the combined attraction effects, as in innumerable 
instances in chemistry, a separation which could not 
have been brought about by a simple one. 

The process of decomposition effected by arable soil 
differs only in one respect from the ordinary chemical 
processes, namely, that in the latter, as a general rule, 
no soluble potash salt is decomposed by an insoluble 
lime salt, in such a manner that the potash is thereby 
made insoluble and the lime soluble. There is evident- 
ly here some other attractive force at work, which alters 
the effect of chemical affinitv- If a solution of phos- 



80 THE SOIL. 

pliate of lime in water containing carbonic acid is 
filtered throngli a funnel filled with earth, the upper- 
most layer of the earth first takes up the phosphoric 
acid or the phosphate of lime from the fluid. Once 
saturated therewith it no longer stops the free passage 
of the dissolved phosphate of lime which now reaches 
the layer beneath ; the latter then again becomes satu- 
rated in the same way, and thus by degrees the phos- 
phate of lime is completely diffused throughout the 
earth in the funnel, so that every particle retains on its 
surface an equal proportion of this substance. If the 
phosphate of lime were of the colour of madder and the 
soil colourless, the latter would now" actually present 
the appearance of a madder lake. Just in the same 
way potash is difiused through the soil when a solution 
of carbonate of potash is filtered through it ; the lower 
layers receive what the upper do not retain. 

There is no need of any special disquisition to show 
that the phosphate of lime contained in a particle of 
bone-earth is diffused in exactly the same way through 
arable soil, with this difference, that the solution of 
j)hos])hate of lime in rain-water containing carbonic 
acid is effected at the very spot where the particle lies, 
and spreads thence downward and in all directions. 

The potash and the silicic acid rendered soluble by 
disintegration, or by the action of water and carbonic 
acid upon silicates, are diffused through the soil in the 
same way, so is ammonia also, wdiich is conveyed in 
rain-water, or is generated by the putrefaction of the 
azotised constituents in the decayed roots from the suc- 
cessive generation of plants grown on a field. 

Every soil must therefore contain potash, silicic acid 
and phosphoric acid in two different forms, namely, in 
cheviical and m physical combination : in the one form, 
infinitely diffused over all the surface of the porous par- 
ticles of the soil ; in the other, in the shape of granules 
of phosphorite, or apatite and felspar, very unequally 
distributed. 

In a soil abounding in silicate and in phosphate of 
lime, which has for thousands of years been exposed to 



FOOD PHYSICALLY AND CHEMICALLY COMBINED. 81 

the dissolving action of water and carbonic acid, the 
component particles will be found everywhere physi- 
cally saturated with potasli, ammonia, silicic acid, and 
phosphoric acid ; and it may occur, as in the case of the 
so-called Russian black-earth, that the phosphate of 
lime dissolved but not absorbed is deposited again in 
concretions, or in a crystalline form in the subsoil. 

In this state of physical combination the alimentary 
substances are manifestly in the most favourable condi- 
tion to serve as food for plants; for it is clear that the 
roots, in all places where they are in contact with the 
soil, will find the necessary nutritive substances in the 
same state of difl'usion and readiness as if these substan- 
ces were in solution in water, but at the same time not 
movable of themselves, and retained in the soil by so 
slight a force that the most trifling dissolvent cause 
brought to bear upon them sufiices to eflect their solu- 
tion and transition into the plant. 

If it is true that the roots of cultivated plants have 
no inherent power to overcome the force Avhich retains 
together potasli and silicic acid in the silicates, but that 
those elements of food only which are in physical com- 
bination with the soil can be taken up and made avail- 
able for nutriment, this explains the difference between 
cultivated and uncultivated ground, or barren sub- 
soil, 

Nothing can be more certain than that the mechan- 
ical treatment of the soil and the influence of the 
weather serve to strengthen the causes which bring 
about the disintegration and decomposition of the 
minerals, and the uniform distribution of the elements 
of food contained in them and rendered soluble. The 
elements chemically combined in the minerals, are re- 
leased from that combination, and in the arable soil 
gradually resulting from this decomposition acquire the 
form in which they are available as food for plants. It 
is evident that only by degrees the rough ground can 
attain the properties of arable soil, and that the time 
required for this change depends upon the quantity of 
nutritive substances present, and upon the obstacles 

4' 



82 THE SOIL. 

which oppose their distribution, or their disintegration 
and decomposition. The perennial plants, and particu- 
larly the so-called weeds, consuming in proportion to 
the time less food, and absorbing longer, will always 
thrive on a soil of this description long before annual 
or summer plants, which in their shorter period of 
vegetation require a far larger amount of nutritive sub- 
stances for their full development. 

The longer a soil is under cultivation, the more it 
becomes suited for the growth of sunmier plants, from 
the recurrence and operation of the causes l)y which 
the nutritive substances are converted from a state of 
chemical into one of physical combination. To be pro- 
ductive, in the fullest sense of the term, a soil must be 
able to aflford food at all points in contact with the roots 
of the plants; and, however small the quantity of this 
food may be, it must necessarily be distributed through 
every part of the soil. 

The power of the soil to nourish cultivated plants is 
therefore in exact proportion to the quantity of mttritive 
substances which it contains in a state of physical satu- 
ration. The quantity of the other elements in a state 
of chemical combination distributed through the ground 
is also higldy important, as serving to restore the state 
of saturation when the nutritive substances in physical 
combination have been withdrawn from the soil by a 
series of crops reaped from it. 

Experience proves that the cultivation of deep-root- 
ing plants, which draw their food principally from the 
subsoil, does not materially impair the fertility of the 
surface soil for a succeeding crop of cereal plants ; but 
the successive cultivation of the latter will, in a com- 
paratively small number of years, render the soil incapa- 
ble of yielding a remunerative crop. 

"With most of our cultivated fields this state of ex- 
haustion is not permanent. If tlie ground is left fallow 
for one or more years, especially if it is well ploughed 
and harrowed during the time, it recovers the power of 
yielding a remunerative crop of cereal plants. 

Chemical analysis leaves altogether unexplained the 



FOOD PHYSICALLY COMBINED. 83 

causes of this fact, so Inglily important to agriculture, 
and which has been fully establislied by the experience 
of several thousand years. If the reason be that cereal 
plants feed on those substances only which arc in physi- 
cal combination in the surface soil, then we can easily 
understand tlie remarkable fact of a field recovering its 
power of production without any supply of manure ; for 
though the nutriment in this form constitutes but a 
small portion of the soil by weight, yet it imparts nutri- 
tive qualities to a large volume of it ; and it is quite 
intelligible that a soil not originally rich in nutritive 
substances physically combined, when drained of them 
by the innumerable underground absorptive organs of 
a plant, must very speedily become imsuited for the 
cultivation of that plant. 

Xow as the cultivated soil is composed in the main 
of ingredients which are identical with the constituents 
of uncultivated ground, and as the agencies affecting 
the decomposition of these ingredients, and the trans- 
position of their constituents affording food to plants 
are in constant operation, it is easy to conceive how, by 
the influence of such causes, an exhausted soil, which is 
in fact nothing else than a soil reduced to its crude state 
previous to cultivation, must regain the properties 
which it had lost. With the conversion of a fresh por- 
tion of the food elements from a state of chemical to 
one of physical combination, the field recovers the 
power of affording food to a fresh vegetation in such 
quantity that the crops are again remunerative to the 
agriculturist. 

An exhausted field which is again rendered produc- 
tive by fallowing, may accordingly be defined as land 
deficient in physically corabined nutritive substances 
necessary for a full crop, while containing an excess of 
such substances in a clurnically comhinecl state. Tlie 
falloiciri'i season^ therefore, means the time in which 
the nutritive substances pass over from the one state to 
the other. It is not tlie amount of nutritive substances 
that is increased in fallowing, but tlie number of parti- 
cles of their constituents capable of affording nutrition. 



84 THE SOIL. 

What is here asserted of all the mineral nutritive 
substances without distinction applies equally to every 
soil constituent required by the plant. The exhaustion 
of a field may often simply depend upon a deficiency of 
available silicic acid for the coming crop of cereal 
plants, while the other food elements may be super- 
abundant. 

It is evident from the nature of the process, that if 
the soil is altogether deficient in disintegrable silicates 
or soluble earthy phosphates, the action of time, the 
plough, and the weather in fallow will not restore fer- 
tility to a field, and that the eflFect of disintegrating 
causes will vary with the time they are in operation, 
and with the composition of the difierent soils. 

It clearly results from the foregoing observations, 
that one of the principal requirements of the practical 
farmer is to know the causes as well as the means 
whereby the useful nutritive siibstances present in his 
field, but not in a form available for nutrition, may be 
rendered diffusible and capable of doing their work. 

The presence of moisture, a certain degree of heat, 
and free access of air, are the proximate conditions of 
those changes by which the nutritive substances in 
chemical combination are made available for the roots. 
A certain quantity of water is indispensable to trans- 
pose the soil-constituents when rendered soluble; 
water, with the co-operation of carbonic acid, decom- 
poses the silicates, and makes the undissolved phos- 
phates soluble and diffusible through the soil. 

Tlie organic remains decaying in the ground afford 
feeble but long-continued sources of carbonic acid ; but 
w^ithout moisture no process of decay can take place. 
Stagnant water, again, which excludes the access of air, 
prevents the generation of carbonic acid ; and the pro- 
cess of putrefaction is attended with the generation of 
heat, whereby the temperature of the soil is perceptibly 
increased. 

By the aid of putrescent vegetable and animal re- 
mains, a field exliausted by culture will regain its fer- 
tility in a shorter time, and the use of farm-yard 



CONDITIONS FOK KENDERING FOOD AVAILACLK, 85 

manure in time of fallow will promote the process. 
The dense shadow cast by a leafy plant tends to retain 
moisture longer in the ground, and thus increases the 
action of the disintegrating agencies during the fallow 
season. 

In a porous soil abounding in lime the putrefactive 
process of organic matter ])roceeds much more quickly 
than in a clay soil ; the ju'esence of the alkaline earth, 
under these circumstances, serving to oxidise the car- 
bonaceous matter, and to convert the ammonia present 
in the soil into nitric acid. 

All kinds of lime, when lixiviated, give up nitrates 
to the water. Nitric acid is not retained by the porous 
earth, as is ammonia ; but it is carried down combined 
with lime or magnesia by the rain-water into the 
deeper layers of the soil. While the formation of nitric 
acid taking place in the ground is useful for plants 
which, like clover and peas, draw their food (here in- 
cluding nitrogen) from a greater depth, yet for this 
very reason fallowing has a less beneficial effect, with a 
view to the culture of cereal plants, upon a lime soil 
rich in animal remains ; for by the conversion of am- 
monia into nitric acid, and its removal, the ground be- 
comes poorer in one of the most important elements of 
the food of plants. The case is conceivable that a field 
of the kind, if not cultivated for a number of years, may 
ultimately have its productive powers impaired by a 
deficiency of nitrogenous food in the soil. 

The cause of tlie exliaustion of a field by the culture 
of any ])lant is always, and under all circumstances, 
dependent upon a deficiency of one or more nutritive 
substances in those portions of the soil which are in 
contact with the roots. A field in which these portions 
are deficient in phosphoric acid in the state of physical 
combination, M-ill be found unsuited for tlie production 
of a proper crop, though it should contain abundance 
of available potash and silicic acid. The same results 
will follow from a want of potash, even though phos- 
phoric and silicic acids be plentiful ; and equally so 
from a want of silicic acid, lime, magnesia, or iron, 



86 THE SOIL. 

even where potash and phosphoric acid are in abund- 
ance. 

When the exhanstion of a field is not caused by the 
absoh;te deficiency of food elements, when even a 
more than adequate supply of all the needful nutriment 
is there, but not in the proper form, and where conse- 
quently fallowing will again render the crop remuner- 
ative, the farmer has means at his disposal to assist the 
action of the natural agencies, whereby the conversion 
of the food elements into the state of physical combina- 
ation is efiected, and thus to shorten the fallowing 
season, or even in many instances to make it altogether 
superfluous. 

We have seen that the diff'nsion of earthy phos- 
phates through the soil is eff'ected exclusively by water, 
which, if containing a certain amount of carbonic acid, 
dissolves these earthy salts. 

Now, there are certain salts, sucli as chloride of 
sodium, nitrate of soda, and salts of ammonia, which 
experience has proved to exercise, under certain condi- 
tions, a favourable action upon the productiveness of a 
field. 

These salts, even in their most dilute solutions, pos- 
sess, like carbonic acid, the remarkable power of dis- 
solving phosphate of lime and phosphate of magnesia ; 
and when such solutions are filtered through arable 
soil, they behave just like the solution of these phos- 
phates in carbonic acid water. The earth extracts from 
these salt solutions the dissolved earthy phosphates, and 
combines with the latter. 

Upon arable soil mixed Avith earthy phosphates in 
excess, these salt solutions act in the same Avay as upon 
earthy phosphates in the unmixed state, that is, they 
dissolve a certain proportion of the phosphates. 

Nitrate of soda and chloride of sodium sufi'er, by 
the action of arable soil, a similar decomposition to 
that of the salts of potash. Soda is absorbed by the 
soil, and in its stead lime or magnesia enters into solu- 
tion in combination with the acid. 

If we compare the action of arable soil upon salts 



MEANS FOK CAUSING THE DIFFUSION OF FOOD. 8T 

of potash and salts of soda, we find that the soil has 
far less attraction for soda than for potash ; so that 
the same volume of earth which -will snffice to remove 
all the potash from a solution will, in a solution of 
chloride of sodium or nitrate of soda of the same alka- 
line strength, leave nndecomposcd three-fourths of the 
dissolved chloride of sodium and half of the nitrate of 
soda. 

If, therefore, a field exhausted by culture, wliicli 
contains earthy phosphate scattered here and there, is 
manured with nitrate of soda or chloride of Godium, 
and by the action of rain a dilute solution of these salts 
is formed, a portion of them will i-emain nndecomposcd 
in the ground, and must in the moist soil exert an in- 
fluence, weak in itself, but sure to tell in the long run. 

Like carbonic acid generated by the putrefaction of 
vegetable and animal substances, and dissolving in 
water, these salt solutions become charged with earthy 
I^hosphates in all places where these occur. Now 
when these phosphates diffused through the fluid come 
into contact with particles of the arable soil not already 
saturated with them, they are thereby withdrawn from 
the solution, and the nitrate of soda or chloride of 
sodium remaining in solution again acquires the power 
of repeatedly exerting the same dissolving and difl'using 
action upon jihosphates which are not already fixed in 
the soil by physical attraction, until these salts are 
finally carried down by rain-water to the deeper layers 
of the soil, or are Totally decomposed. 

It is M"ell known that chloride of sodium is present 
in the blood of all animals, and that it plays a part in 
the processes of absorption and secretion ; hence it may 
be regarded as indis]^eiisable for these functions. We 
find also that nature has endowed fodder-plants, tuber- 
ous and root-plants, which serve more particularly as 
food for cattle, with a greater power of taking up 
chloride of sodium from the soil than is possessed by 
other plants ; and agricultural experience shoAvs that 
the presence of a small amount of common salt is 
favourable to the luxuriant growth of these plants. 



88 THE SOIL. 

Of nitric acid, it is generally assumed that it may, 
like ammonia, serve to sustain the body of the plant. 
Thus, chloride of sodium and the nitrates act in two 
distinct ways : one direct, by serving as food for the 
plant ; one indirect, by rendering the phosphates avail- 
able for the purposes of nutrition. 

The salts of ammonia act upon earthy phosphates 
in the same way as the salts just mentioned, but with 
this distinction, that their power of dissolving phos- 
phates is far greater ; a solution of sulphate of ammo- 
nia will dissolve twice as nmch bone-earth as a solution 
of an equal quantity of chloride of sodium. 

However, as regards the phosphates in the soil, the 
action of the salts of ammonia can hardly be more 
powerful than that of chloride of sodium or nitrate of 
soda, since the salts of ammonia are decomposed by the 
soil much more speedily, and often even immediately ; 
so that, as a general rule, no solution of such a salt can 
be said to be actually moving about in the soil. But 
as a certain volume of earth, however small, is required 
to decompose a given quantity of salts of ammonia, the 
action of those salts upon this small volume of earth 
must be all the more powerful. While, then, the 
action of salts of ammonia is barely perceptible in 
the somewhat deeper layers of the arable surface soil, 
that which they exercise on the uppermost layers is so 
much the stronger. Feichtinger observed that solu- 
tions of salts of ammonia decompose many silicates, 
even felspar, and take up potash from the latter. Thus, 
by their contact with the arable soil, they not only 
enrich it with ammonia, but they effect, even in its 
minutest particles, a thorough transposition of the nu- 
tritive substances required by plants. 

The vegetable and animal remains in a soil seem to 
exercise a remarkable influence upon the diffusion of 
silicates. The experiments made on this point show 
that the absorptive power of an arable soil for silicic 
acid is in an inverse ratio to the amount of organic re- 
mains in it ; so that a soil rich in such remains will, 
when brought into contact with a solution of silicate of 



DEFICIENCY OR EXCESS OF SOLUBLE SILICIC ACID. 89 

potash, leave a certain amount of silicic acid imabsorbcd, 
■whereas an equal bulk of soil poor in organic remains 
Avill take up the whole of the silicic acid in the solution. 
The incorporation of decaying vegetable and animal 
matter will, therefore, in a soil conlaining disintcgrable 
silicates, lirst of all accelerate the decomposition of the 
silicates, by the action of the carbonic acid generated in 
the process of decay, and then as these substances 
diminish the absorptive power of the soil for silicic acid, 
as soon as this acid has passed into solution, it is dis- 
tributed through the soil more widely than would have 
been the case had these substances not been present. 

On many fields poor in clay, the growlh of grass 
for several years will, in consequence of the organic 
matters collecting in the soil, which serve to promote 
the distribution of the silicic acid, act more favourably 
on a succeeding crop of a cereal plant than a plentiful 
application of farm-yard manure, whose organic con- 
stituents, quite irrespective of the silicate of potash in 
the straw, are always in operation to effect the same 
object. On many other fields, especially on those 
abounding in lime, where there is no actual deficiency 
of silicic acid, but the quantity present is not properly 
distributed through the soil, a dressing of pulverised 
turf-waste often produces an equally favourable effect 
on a succeeding cereal crop as a plentiful application 
of farm-yard manure. 

Deficiency or excess of soluble silicic acid in the 
ground is equally injurious to the growth of cereal 
plants. A soil which would answer very well for 
horse-tail or common reed {Arundo phragmitcs, plants 
abounding in silica) is not on that account equally well 
suited for the superior kinds of meadow grass, or for 
cereals, although these demand a rich supply of silicic 
acid. Such a soil may be improved by drainage, 
which, by giving free access to air, deconii)Oses and 
destroys the organic substances present in excessive 
quantity ; or it may derive benefit from a dressing of 
marl, or of burnt lime, slaked, or fallen to powder by 
moist air. 



90 THE SOIL. 

Hydrated silicic acid loses its solubility in water by 
simple drying, and it frequently happens that the 
drainage of a marshy held will cause the siliceous j)lants 
(reeds and horsetail) to disappear. The action exerted 
upon the soil by hydrate of lime, or by lime slaked or 
fallen to powder in the air, is twofold. On a soil rich 
in humus constituents the lime combines, in the first 
place, with the organic compounds present, which have 
an acid reaction ; it neutralises the acid of the soil, 
thereby causing the speedy disappearance of many 
weeds, such as bog-moss {Sphagmim) and reed-grasses, 
which flourish in a sour soil of this kind. Simple con- 
tact wath acids powerfully promotes the oxidation of 
metals (copper, lead, iron), while contact with an alkali 
prevents it (iron coated with a dilute solution of carbon- 
ate of soda will not rust). Upon organic substances, 
the action is the very reverse: acids prevent, and 
alkalis promote, oxidation or decay. Excess of lime 
causes the aforesaid destruction of the humose con- 
stituents. 

In the same degree as the acid humus, by the action 
of lime, disappears from the ground, the absorptive 
power of the latter for hydrated silicic acid is increased ; 
and the excess of this acid present loses its mobihty in 
the soil."'^ 

The action of lime, as we see, is so complex, that 
from its favourable influence upon one field, it is 
scarcely ever possible to form an opinion of its probable 
action upon another field, the condition of which is 
unknown. This is possible only when the causes of its 
favourable action in the first case are clearly understood. 

When lime has improved the condition of a field, 
simply by neutralising the acid state of the soil, and 

* In an experiment made specially for the purpose, it was found that a 
litre (about a quart) of forest soil, containing 30 per cent, of humose con- 
stituents, absorbed from a solution of silicate of potash only 15 milli- 
grammes of silicic acid. But the same soil mixed with 10 per cent, of 
washed chalk (carbonate of lime) absorbed 1140 milligrammes; and when 
tnixed with 10 per cent, of slaked lime instead of chalk, the absorptive 
power was increased to such a degree, that a litre absorbed 3169 milli- ' 
grammes of silicic acid. 



BENEFICIAL ACTION OF LIME. 91 

destroying the injurious excess of vegetable remains, the 
farmer will in vain expect a favourable result from the 
application of lime in the following years, unless the 
same causes should recur which had originally impaired 
the fertility of the field. 

In a soil wlicrein there are putrescent and decaying 
substances not a single plant will thrive, except mush- 
rooms ; and it seems that every chemical process going 
on in the neighbourhood of roots disturbs that of their 
own. Decaying substances in excess, by generating 
too much carbonic acid, injure even those plants which 
thrive particularly well in a humose soil containing a 
moderate quantity of humns.* 

Upon deep-rooting plants, such as turnips, clover, 
sanfoin, peas and beans, organic matters accumulating 
largely in the subsoil act very injuriously, especially in 
clay, where they decay much more slowly than in a 
lime soil. The process of decay is communicated to the 
sickening roots, in M'hich spores of fungi find a suitable 
soil for their developement. "When turnips are thus 
affected, they become the prey of certain insects, which 
deposit their eggs in the roots, causing in their develope- 
ment a strange alteration and disturbance of the vege- 
table process ; for in the diseased parts spongy tmuours 
arise, the inner substance of which becomes soft and 
emits a bad smell, and in this state serves to nourish 
the larva of the small fly. 

All these processes, however obscure in themselves, 
are put an end to by applying lime to such a field ; a 
proper lime dressing will always attain this object. 
Fields that are particularly rich in organic remains 



* Gasparini sowed a few frrains of spelt in a pot with washed earth 
from Vesuvius; these produced plants which continued to f;jro\v in a 
healthy state. In another pot, filled with the same earth, he introduced a 
piece of bread ; in this, all the roots in the immediate vicinity of the 
mouldering bread died away, and the other roots seemed to have turned 
oH" towards the sides of tlic pot. It is clear that spelt would not prow in a 
soil copiously mixed with bread; and if the decaying roots left by a spelt 
crop have the same effect, it is not difficult to conceive how the decaying 
remains which a plant leaves in the ground, may injuriously aficct its own 
growth, or that of other plants. (Russell.) 



92 THE SOIL. 

require a mucli larger supply of lime than others, to 
effect their restoration to a healthy state. 

It is certain, that in all such cases, the beneficial 
action of the lime is not attributable to an original 
deficiency of that body in the soil for plants growing on 
it ; for in that case, considering the rapidity with wdiich 
it is difiused through the soil, the efitect would manifest 
itself very soon, and even in the course of the first year. 
But it takes several years before the favourable change 
in the condition of the soil is efl:ected ; proving that the 
lime operates, not simply as food, but by producing an 
alteration in the soil, which requires time, that is, a 
succession of operations. 

On a drained marshy soil, in which lime has dimin- 
ished the excess of hydrated silicic acid, a second appli- 
cation will not produce the same result, because the 
offensive substances, once removed, will not return; 
while on a heavy, stifiT clay or loam, the application 
may be repeatedly successful. These kinds of soil are 
thereby made more friable and richer in available 
potash. The nature of the change produced is most 
clearly shown in the hydraulic lime obtained by cal- 
cining native cement stones (a hard marl). These 
cement-stones consist of a mixture of lime and clay, the 
former being in larger proportion than in calcareous 
clay soil. After burning, if it is stirred up with a large 
quantity of water, the separated potash im])ar{s to the 
fluid ail the properties of a weak lye. Glay which 
before calcination with lime refused to dissolve in 
acids, is, after calcination, soluble in acids to the whole 
extent of the silicic acid present. 

A calcareous clay soil withdraws from a solution of 
silicate of potash much less potash after calcination than 
before, but a much larger quantity of silicic acid.* 

Besides the chemical aacents mentioned here, wdiich 



* At Bogenhausen, near Munich, loam was calcined in the air, and 
brought into contact with a solution of silicate of potash ; before calcina- 
tion, a litre of this earth took up 1148 milligrammes of potash, and 2007 
milligrammes of silicic acid ; after calcination, no potash, and 3230 milli- 
grammes of silicic acid. 



THE ROOT GOES IN SEARCH OF FOOD. 93 

the farmer may employ to effect the proper distribution 
of the nutritive substances stored up in his field, and to 
make the earthy ])hosphates, the potash, and the silicic 
acid available to the roots of the plants, ho further im- 
proves his land by the mechanical operations of a<^ricul- 
ture, and by removing from the soil all obstacles that 
hinder the spreading of the roots, as Avell as those in- 
jurious agencies which interfere with their normal ac- 
tivity, or endanger their healthy condition. 

The effect produced by breaking up the ground by 
the plough, spade, hoe, harrow, and roller, depends 
upon the fact, that the roots of plants go in search of 
their food; that the nutritive substances have no loco- 
motion of their own, and cannot of themselves leave 
the place in which they are. The root, as if it had eyes 
to see, bends and stretches in the direction of the nntri- 
ment ; so that the number, thickness, and direction of 
its filaments indicate the precise spots where they have 
obtained food.* 

The young root forces its way, not like a nail driven 
with a certain force into a plank, but by the addition 
of successive layers, which increase its mass from within 
outwards. 

The new substance, which lengthens the extremity 
of the root, is in contact with the soil. The newer the 
cells forming at the extremities, the thinner are their 
walls ; as they grow older, the cell-Avalls thicken, and 
their outer surface, becoming more woody, is coated in 
many cases with a layer of corky substance, which, 
being impenetrable by water, affords, to the soluble 
matter deposited within, some protection against os- 
motic influences. 

* Pieces of lione are often found completely enclosed by a network of 
turnip-roots. It is difficult to understand how this could have been accom- 
plished otherwise than by an attraction between the sponjijioles and the 
suljstance of the bone. The colls, or their contents, are incos.^antly 
attracted by the fresh surface of a substance, for which the contents have 
a chemical attraction. 

It is owinj^ to this attraction that the roots wind round the piece of 
bone ; they form a root-l)all rolled, not from without, but from within, by 
the new cells constantly formed upon contact with a substance for which 
they possess a chemical attraction. (Russell.) 



94: THE SOIL. 

Absorption of nutriment from the soil is effected by 
the extremities of the roots, whose fluid contents are 
separated from the earthy particles around them by an 
exceedingly thin membrane alone ; and the contact of 
the two is the more intimate, as the root-tibre during 
its formation exerts upon the earthy particles a pres- 
sure sufiiciently powerful, under certain circumstances, 
to push them aside. The evaporation of water from the 
leaves produces a vacuum within the plant, wliereby a 
draught is created, which powerfully assists the con- 
tact of the moist earthy particles with the cell-wall. 
The cell and the earth are pressed against each other. 
Between the fluid contents of the cells and the nutritive 
substances physically combined in the earthy particles, 
there manifestly exists a strong chemical attraction, 
which, with the cooperation of carbonic acid and w^ater, 
causes the transference of the incombustible matters 
into the system of the plant. 

By the powerful chemical attraction of any body, 
we understand its entering into a chemical combination, 
in which it loses its original properties and acquires 
new ones. In the case of potash, lime, and phosphoric 
acid, such a combination must take place immediately 
upon their passage into the cell ; for, as already stated, 
the sap of the roots is always slightly acid. In the sap 
of the root-shoots of the vine, we can always detect 
bitartrate of potash ; in that of others, oxalate or citrate 
of potash, or tartrate of lime; but we never find these 
bases combined in such saps -with, carbonic acid, nor 
can phosphate of lime or magnesia be detected. If the 
fresh sap of the potato-tuber is mixed with ammonia, 
no ^precipitate of phosphate of magnesia and ammonia 
is produced ; but this precipitate makes its appearance 
as soon as the fermentation of the sap has destroyed 
the (azotised) substance with which the phosphate of 
magnesia is combined. 

Careful mixture and distiibution of the nutritive 
substances present in the soil, are the most important 
means of rendering them effective. 

A piece of bone, weighing half an ounce, placed in 



DISTRIBUTION KliNDERS FOOD EFFECTIVE. 95 

a cubi(! foot of earth, lias no perceptible influence upon 
its fertility ; but when uniformly distributed and phys- 
ically combined with the minutest ])articles of the same 
earth, it attains a nuiximum of eflicacy. The influence 
of the mechanical operations of agriculture u])Oii the 
fertility of a soil, however imperfectly the earthy parti- 
cles may be mixed by the process, is remarkable and 
often borders upon the marvellous. The spade, which 
breaks, turns, and mixes the soil, makes a field much 
more fruitful than the plough, which breaks, turns, and 
displaces the earth, without mixing it. The effect of 
both is increased by the harrow and the roller, so that, 
in the very same places where a crop has grown during 
the preceding year, a fresh crop will find nutriment ; in 
other words, the earth is not yet exhausted. 

The action of chemical agents in distributing the 
food-elements of plants is still more powerful than that 
of the mechanical. By applying, in proj)er quantities, 
nitrate of soda, salts of annnonia, and chloride of sodi- 
um, the flmner not only enriches his field with materials 
capable of taking part in the nutrition of plants, but he 
also effects a distribution of the ammonia and potash, 
thereby replacing or aiding the mechanical work of the 
plough, and the influence of the weather in the ^nie of 
fallow. 

"We are in the habit of calling ' manures ' all those 
materials which, when applied to our fields, increase 
the crops ; but the same effect is produced by the 
plough. It is evident that the mere fact of a favour- 
able influence exerted by chloride of sodium, nitrate of 
Boda, salts of ammonia, lime, and organic matter, 
affords no conclusive proof that these have acted as 
nutritive substances. The work performed by the 
plough may be compared to the mastication of food by 
those special organs with which nature has endowed 
animals ; and nothing can be more certain than that 
the mechanical operations of agriculture do not add to 
the store of nutritive substances in a field, but that 
they act beneficially by preparing the existing nutri- 
ment for the support of a future crop. With equal 



96 THE SOIL. 

certainty we know that chloride of sodium, nitrate of 
soda, salts of ammonia, humus, and lime, beside the ac- 
tion peculiar to their elements, perform also a kind of 
digestive function comparable to that of the stomach in 
animals, and in which they may partly replace each 
other. These substances, tlierefore, act beneficially upon 
those kinds of soil only in which there is a defect, not 
in the quantity, but in the form and condition of the 
nutritive elements ; and they may accordingly in their 
permanent action be replaced by a mechanical commi- 
nution, or exceedingly fine pulverisation of the soil. 

The true art of the practical farmer consists in 
rightly discriminating the means which must be ap- 
plied to make the nutritive elements in his field efl'ect- 
ive, and in distinguishing these means from others 
which serve to keep up the durable fertility of the land. 
He must take the greatest care that the physical condi- 
tion of his ground be such as to permit the smallest 
roots to reach those places where nutriment is found. 
The ground must not be so cohesive as to prevent the 
spreading of tlie roots. 

In a stiff, heavy soil, plants with fine, slender roots 
will never thrive well, even though the supply of nutri- 
tive substances be ample ; and in these circnmstances, 
the beneficial influence of green manure and fresh sta- 
ble dung is unmistakeable. The mechanical condition 
of the soil is, in fact, altered in a remarkable w^ay by 
the ploughing in of plants and their remains. A stiff 
soil loses thereby its cohesion, becoming more friable 
and crumbling, than it would be by the most diligent 
ploughing. In a sandy soil, on the other hand, a cer- 
tain cohesion is hereby produced. Every stem and 
leaf of the green-manure plants ploughed in, opens up, 
by its decay, a road by which the delicate roots of the 
cereals may ramify in all directions to seek their food. 
Hero, too, we must ahvays remember, that the effect 
calculated to be produced is a question of degree. In 
many fields, the roots left in the soil of a fine crop of 
green forage plants will suffice to improve a succeeding 
cereal crop ; and a field from which a crop of lupines 



FAVOTTRABLE ACTION OF CLOVER AND TURNIPS. 97 

has been taken, may possibly give as fine a succeeding 
cereal crop as a iield of equal extent in wliich the lu- 
pines have been plouglieJ in. 

All these observations tend to show the great im- 
portance of the mechanical conditions whicli impajt fer- 
tility to a soil not originally delicient in the means of 
nourishing plants ; and that a comjjaratively poorer but 
well-tilled soil, if its physical condition is mui'c favour- 
able for the activity and developement of the roots, 
may yield a better harvest than richer land. In like 
manner, it often happens that the cultivation of a bulb- 
ous plant renders the ground better suited ibr a follow- 
mg cereal, and that a winter crop succeeding a green 
forage plant, turns out all the better, the richer the 
previous green forage crop has been, or rather the roots 
left by it. 

Clover and turnips act favourably upon a succeed- 
ing winter crop, as their long hardy roots move the 
subsoil, which is inaccessible to the plough, and open 
it for the roots of wheat. Here the favourable influ- 
ence upon the physical condition of the soil far out- 
weighs, for the wheat-plant, the injurious efiect of the 
decrease rn the quantity of the chemical conditions re- 
sulting from the previous turnip and clover crops. 
Facts of this nature have but too often misled practical 
agriculturists to surmise that the physical condition is 
everything, and that a thorough working and pulver- 
isation of the soil will suftice to command a good crop. 
These views, however, have always been refuted by 
time ; and all we can consider established is this, that 
for a series of years the restoration of a proper physical 
condition in the soil is as important for the productive- 
ness of many fields as manuring, and often more so. 

The influence of a proper physical condition of the 
soil upon the produce can hardly be more convincingly 
proved than by the facts which agricultuie has derived 
from the drainage of land, under which we comprise 
the removal of the subsoil water to a greater depth, and 
the quicker withdrawal from the arable soil of the por- 
tion circulating in it. A great many fields unsuited, 



98 THE SOIL. 

by tlieir constant humidity, for the cultivation of cereal 
plants and the superior kinds of forage grasses, have 
been reclaimed by drainage, and made iit to produce 
food for man and beast. When the farmer, by means 
of drainage, keeps within bounds the amount of water 
in his fields, he controls its injurious influence at all 
seasons ; and by the speedier removal of the water, 
which soaks the earth and destroys its porosity, a path 
is opened for the air to reach the deeper layers of the 
ground, and to exercise upon these the same beneficial 
influence as upon the surface soil. 

In winter, the earth at a depth of 3 to 4 feet is 
warmer than the external atmosphere ; hence the air 
coming up from the drain-pipes may contribute to keep 
the temperature of the arable surface higher than it 
would be without this current of air. The air in the 
drains is generally richer in carbonic acid than is the- 
case with atmospheric air. 

The efii'ect which drainage produces upon the fer- 
tility of land may in itself he deemed a proof that 
plants cannot derive their food from the water moving 
about in the soil. This view is strongly supported by 
the analysis of well, drain, and spring water. (See Ap- 
pendix D.) 

The drainagfe-waters contain all the substances which 
the rain-water, percolating the surface soil, is capable 
of dissolving : they contain various salts in trifling pro- 
portions, and among these mere traces of potash ; am- 
monia and phosphoric acid are generally absent. In 
analyses specially made for this purpose, Thomas Way 
found that in four (drainage) w^aters no appreciable 
quantity of potash could be detected in 10 pounds of 
water ; three other waters were found to contain from 
2 to 5 pounds of potash in 7,000,000 pounds of water. 
In three waters no appreciable quantities of phosphoric 
acid could be discovered : four other waters were 
found to contain 6 to 12 pounds of phosphoric acid, 
and 0*6 to 1*8 pounds of ammonia in 7,000,000 pounds 
of water. In a similar series of analyses, Krocker 
found that in six drainage-waters no appreciable traces 



ANALYSIS OF DRAINAGE WATICKS. 09 

of phosphoric acid or ammonia could be detected ; 
while four otlier drainage-waters were found to contain 
not above 2 parts, and two others severally 4 and G 
parts of potash, in 1,000,000 parts of water. 

The tacts now stated are corroborated by a series of 
direct and most instructive experiments made by Dr. 
Fraas, to ascertain what substances the rain falling in 
the six summer months takes up from the surface soil 
and carries down into the deeper layers. 

In lysimetcrSy or underground rain-gauges specially 
constructed for the purpose, a collection was made of 
the rain-water, which trickled through a layer of earth, 
6 inches deep by 1 square foot in transverse section, 
from the 6th April to the 7th October. The rain-gauge 
kept at a neighbouring observatory indicated, up to the 
1st October, a fall of rain amounting to 480'7 millime- 
tres (18-75 inches).* 

Four lysimetors M'ere filled with the same earth 
taken from the subsoil of the stiff clay at Bogenhausen ; 
in two of them (III. and IV.) the earth was manured 
with 2 pounds of cow's dung ; the other two were left 
unmanured. Nos, II. and IV. were sown with barley. 

Calculated upon a square metre (10-75 square feet) 
of ground, the following were found to be the quanti- 
ties of water that had passed through. Dr. Zoeller 
determined the amount of soluble substances contained 
in the water ; the quantities of phosphoric acid and 
ammonia were too small to be appreciable : — 

* The lysiraetcr consisted of a square box, open at the top, closed at 
the bottom ; at a depth of six inches from the open top a sieve was in- 
serted, from which, up to the rim, the box was filled with earth. The 
rain falling upon a square foot of surface, and trickling through the six 
inches of earth, was collected beneath the sieve, in the box. The box was 
buried in an open field, up to the border, so that the earth in it was level 
with the surface of the field. Two lysimeters were filled with lime soils 
from the banks of the Isar ; but one of them broke, and the water could 
not be collected : hence the results obtained from the other lost their im- 
portance as a comparative experiment. 



100 



THE SOIL. 



Quantity of perco- 
lated water .... 

Quantity of potash 
contained 

Or, per hectare, of 
24- acres .... 



Lysimeter. 



unmamired: 
and without 
veiretation. 



Litres. Pints. 
218=^383-68 



II. 

uninanurc(i: 

sown with 

barley. 



Litres. Pints. 
213=374-88 



Grams. Grains. Grams. Grains. 
0-516=:8-0 0-434 = 0-7 



Kilog. lbs. avr. 
5-16 = 11-35 



Kilog. lbs. avr. 
4-34 = 9-5 



IIL 


IV. 


manured: 


manured: 


without 


sown with 


vegetation. 


barley. 



Litres. Pints. Litres. Pints. 
304 = 535 i 144 = 253-5 



Grams. Grains. Grams. Grains. 
1-265=19-5 1 0-552 = 8-5 



Kilog. lbs. avr. Kilog. lbs. avr. 
12-65 = 27-81 5-52=12-1 



In lysimeters I. and II. nearly the same quantities 
of water percolated througti tlie eartli ; in tlie two 
others the difference is great ; the two former alone, 
therefore, admit of comparison as regards the solvent 
power of the water. 

These experiments show that less than one-half of 
the rain falling on the field under the given conditions, 
reached a depth of 6 inches ; and that, calculating for 
1 million parts of water, the unmanured soils I. and II. 
gave respectively 2-37 and 2"03 pounds, the manured 
soils III. and IV. 546 and 3-82 pounds of potash. The 
quantities of potash in the manured soils do not exceed 
the average quantity of potash found in drainage- 
water (Krocker). 

The barley grown in the earth of lysimeter II. pro- 
duced, per square metre, 137*3 grammes (2120 grains) 
of barley-corns, and 147*9 grammes (2272 grains) of 
straw, containing in their ashes (the corns in 2*47 per 
cent., the straw in 4*95 per cent, of ash) :- 



In the corns 
" straw 

Total 



0-823 grammes 12-6 grains of potash 
1-410* " 21-8 " 



2-233 



34-4 



Tlie quantity of potash absorbed by the water from 
the earth in the first lysimeter, which was not sown 
with barley, amounted altogether to 0.516 gramme (8*0 
grains) ; in the second lysimeter to 0*434 gramme (6*7 



MATTERS DISSOLVED BY KAIN ^VATER IN SOIL. 101 

grains). The difference is 0*082 gramme (1*3 grains). 
If we think ourselves warranted in concluding from 
this, that the diminution in the quantity of potash in 
the water of the second lysimcter resulted from its ab- 
sor})tion by the roots of the barley, we should be neces- 
sarily led to infer that the plants received — 

By the agcncv of the percolating water 0'082 grammes 1"3 grs. 
Direct from tiie soil .... 2.151 " 33-2 " 

Total . . . 2-233 " 34-5 

and, accordingly, 964 per cent, direct from the soil, 
and 3-6 per cent, from the water ; that is, 2Y times 
more from the former than from the latter. 

Let us now assume, from the results obtained with 
the third h'simeter, which was filled with earth richly 
manured with cow-dung, that the rain-water falling on a 
surface of one hectare (2|- acres) of land, dissolves, out 
of a layer of arable surface soil 6 inches deep, 12*65 
kilogrammes (27*8 lbs.) of potash ; and let us compare 
with this the quantity of potash withdrawn from a hec- 
tare of ground by a potato or turnip crop. We know 
that an average potato crop from a hectare contains in 
the tubers 204 kilogrammes (449 lbs.) of ash, of which 
100 kilogrammes (220 lbs.) are potash ; and an average 
turnip crop, 572 kilogrammes (1258 lbs.) of ash, of 
which 248 kilogrammes (545 lbs.) are potash ; and we 
easily perceive that, even had the entire amount of the 
potash dissolved by the rain been conveyed into the 
plants to serve as food, yet this would be sufficient to 
supply, with the necessary potash, only the eighth part 
of the potato tubers and the twentieth part of the tur- 
nips severally produced on a hectare of land. The 
amount of potash in the percolated water shows the 
quantity of potash which the Avatcr could possibly ab- 
sorb ; and as comparatively but a small portion of the 
percolating water comes in contact with the roots of 
the plants, and can give up potash to them, it is clear 
that the constituents of the solution moving about in 
the soil have but a very trifling share in the process of 
nutrition, while the absence from it of ammonia and 



102 . THE SOIL. 

phosphoric acid is of itself sufficient to prove that these 
materials in the soil cannot change their place. Tlie 
ground must contain a certain amount of moisture to 
be able to furnish food to plants ; but it is not necessary 
for their growth that the water should be free to move 
about. It is well known that stagnant water in the 
soil is injurious to most of the cultivated plants ; and 
the favourable efi'ect upon their growth produced by 
draining just depends on this, that an outlet is opened 
to the water moving by the force of its own gravity, 
and the earth is moistened by that water only which is 
retained by capillary attraction. 

If we regard the porous earth as a system of capil- 
lary tubes, the condition which must render them best 
suited for the growth of plants is unquestionably this, 
that the narrow capillary spaces should be filled with 
water, the wide spaces with air, and that all of them 
should be accessible to the atmosj)here. In a moist 
soil of the kind, affording free access to atmospheric 
air, the absorbent root-fibres are in most intimate con- 
tact with the earthy particles ; the outer surface of the 
root-fibres may here be supposed to form the one, the 
porous earthy particles the other wall of a capillary 
vessel, the connection between them being effected by 
an exceedingly thin layer of water. This condition is 
equally favourable for the absorption of fixed and of 
gaseous elements of food. If, on a dry day, a wheat or 
barley-plant is cautiously pulled up from a loose soil, a 
cylinder of earthy particles is seen to adhere like a 
sheath round every root-fibre. It is from these earthy 
particles that the plant derives the phosphoric acid, pot- 
ash, silicic acid, &c., as well as the ammonia. These 
substances are introduced into the plant by means of 
the thin layer of water, the molecules of which are in 
motion only in so far as the roots exercise an attractive 
power upon them. 

From the composition of spring-water, and the 
water of brooks and rivers, every single drop of which 
has been in contact with rocks, or with the soil of for- 
ests and fields, we see what exceedingly minute quanti- 



WHY SALTS ARE FOUND IN STAGNANT POOLS. 103 

ties of phosplioric acid, ammonia, and potash are taken 
up by water from the eartli. In the analysis of water 
taken from six difterent springs, Graham, Miller, and 
Hofmann found no appreciable traces of ammonia and 
phosphoric acid. In the water of Whitley, there was, 
in 37,000 gallons (370,000 pounds English), 1 pound of 
potash, or 1 kilogramme in 135 cubic metres : just the 
same in 38,000 gallons from the Critchmere spring ; in 
32,000 gallons fron:u Yelwool ; in 145,000 gallons from 
Hindhead ; in 55,000 gallons from the Hasford Mill- 
brook ; and in 17,700 gallons from the spring near Cos- 
ford House. The water of the Bruntlial spring, near 
Munich, which is used for drinking in a large portion 
of the city, contains no ammonia, no i^hosphoric acid, 
and in 87,000 pounds, 1 pound of potash. 

From these and other analyses of spring, well, and 
dramage water, we are not warranted in concluding 
that potash, ammonia, and phosphoric acid are deficient 
in the water of all springs, brooks, and rivers ; on the 
contrary, it is quite certain that the water in many 
marshes contains both potash and phosphoric acid in 
notable quantities.* 

Tlie presence of potash, phosphoric acid, iron, and 
sulphuric acid, in the water of stagnant pools, is easily 
explained. 

* Thus a litre (1'75 pints) of water taken from an artificial pond in the 
Botanic Garden at Munich, left a residue of 0"425 gramme ((j'5 grains), 
■which contained, in 100 parts — 

Lime 35-000 

Magnesia ....... 12'264 

Chloride of sodium lO'lOO 

Potash 3-970 

Soda . . . . _ . . . 0-471 

Sesquioxide of iron with alumina . . 0'721 

Phosphoric acid. 2-G19 

Sulphuric acid 8-271 

SUicic acid 3-240 

Incombustible constituenta .... 76-656 
Wateriest 23-344 

100-000 



104 THE SOIL. 

In a stagnant pool or bog are gradually collected 
the remains of dead generations of plants, the roots of 
which have drawn a quantity of mineral matter from a 
certain depth of the soiL Ihese vegetable remains un- 
dergo decomposition at the bottom of the pools, and 
their inorganic elements, or ash-constituents, are dis- 
solved by the aid of carbonic acid, and perhaps also of 
organic acids. They remain dissolved in the water, 
when the surrounding mud and the earth in contact 
with this solution have been completely saturated with 
them. 

Scherer found in the three wells at Brlickenau all 
the substances contained in the water above-mentioned, 
of the Botanic Garden pond, besides acetic, formic, 
butyric and propionic acids. The mountains all around 
Briickenau are formed of variegated sandstone {Bvnter 
sandsiein) ; the vegetation of the whole surrounding 
country is most luxuriant, resembling the primeval for- 
ests ; there are numerous oak-lands and beech-lands, 
with trees nearly a thousand years old. Hence Scherer 
is led to attribute the composition of the well-water at 
Briickenau to the solvent action of rain percolating 
through a humose soil rich in decaying vegetable sub- 
stances. (' Annal. der Chem. und Pharm.' i. c. 285.) 

It is clear that wherever conditions have been at 
work similar to those under which the bog-water in the 
Botanic Garden of Munich and the wells of Briickenau 
have been formed, the water found on the surface of 
the earth, in pools, springs, or brooks, will contain in 
the most varying proportions nutritive elements useful 
to plants, such as phosphoric acid and potash, which 
are not found in other waters. In like manner, an 
arable soil rich in vegetable remains, in which, from 
the processes of decay incessantly going on, products 
of an acid character are generated, will be able to give 
up, to the rain-water percolating through it, phosphoric 
acid and alkalies, which are thus carried down to the 
deeper layers, and appear in the drainage water. The 
quantity of these substances dissolved in the water will 
depend upon the condition of the soil on which the 



FEKTILISING EFFECT OF BOG SOIL AND ^^CT>. 105 

plants grow, tlie asli-constitucnts of which arc carried 
away by the rain-water, from their decaying remains. 
Where the gronnd is rocky, covered with a thin coat- 
ing of earth and a thick clothing of foliage, the water 
which runs off will carry down to the lower layers all 
the more fixed elements of vegetable food, in propor- 
tion as the layer of earth itself retains less of them. 
The finer earthy particles of such a soil, washed away 
by heavy rains, are carried down by torrents to the 
valleys and low lands, and form a soil of all degrees of 
fertility according to their chemical condition, which 
determines their power of absorbing dissolved nutritive 
substances. But these layers of earth formed from the 
mud borne down by the torrents will always either be 
saturated, or gradually become saturated with the nu- 
tritive substances contained in the water, from which 
they are deposited. This, perhaps, explains the differ- 
ence in the fertilising effects of the waters used for irri- 
gating meadows, which must necessarily vary very 
much according to the source of the water ; that which 
has collected on hills covered with a rich vegetation, or 
has been derived from overflowing stagnant pools, will 
doubtless convey manuring matters to the meadow- 
lands ; whilst water flowing from bare mountains can- 
not, in this particular respect, exert any action upon 
the increase of the grass croj). If such increase takes 
place notwithstanding, the cause must be sought else- 
where. 

In many places bog-soil, and the mud from ditches, 
stagnant waters and jDonds, arc highly esteemed as fer- 
tilising agents ; and their influence is explained by the 
fact, that their smallest particles are saturated with 
manuring matters, or elements of the food of plants. 
The same remark applies to the fertility of many tracts 
of cleared wood-land, where the soil for forty or eighty 
years, or even longer, has received fz'om the layer of 
foliage and vegetable remains decaying on it, a certain 
supply of ash constituents, drawn from a great depth, 
which are retained by the upper layers of the porous 
soil, and serve to enrich it. 

6* 



106 THE SOIL. 

The injury done to wood-lands by raking away the 
leaves cannot be explained merely upon the assumption 
that the soil is deprived of its ash-constituents, which 
are taken away with the foliage ; for, in themselves, 
the fallen leaves and twigs are poor in nutritive sub- 
stances, esjDecially potash and phosphoric acid ; and 
besides, these elements do not reach the deeper layers 
of the soil, where they might be again absorbed by the 
roots. The injury is, perhaps, rather attributable to 
the fact, that the remains of leaves and plants consti- 
tute a lasting source of carbonic acid, which, carried by 
rain to the deeper layers, must powerfully contribute 
to disintegrate and decompose the earthy particles. In 
a dense wood, where the air is more rarely renewed 
than in the open plain, this supply of carbonic acid is 
important ; moreover, the thick carpet of leaves pro- 
tects the ground from being dried by the air, and main- 
tains it in a permanent state of moisture, particularly 
useful to foliaceous trees, which exhale from their 
leaves larger quantities of water than the coniferous 
plants. 

To understand the operations of agriculture, it is 
indispensably necessary that the farmer should have 
the clearest knowledge of the manner in which plants 
derive their nutriment from the soil. 

The opinion that the roots of plants extract their 
food immediately from those portions of the soil which 
are in direct contact with their absorbent surfaces, does 
not imply that potash, lime, or phosphate of lime, in 
the solid, undissolved state can penetrate the membrane 
of the cells ;* nor does it imply that the nutritive sub- 

* If a glass vessel is filled to the brim with water, in which are a few 
drops of hydrochloric acid, and covered closely with a piece of bladder, so 
that the water moistens the bladder and no air is left between them, and 
the outside of the bladder is carefully dried, it may then be seen how a 
solid body, without the cooperation of a fluid from the outside, can make 
its way through the bladder to the water in the glass. For if a little chalk 
or finely-pulverised phosphate of lime is strewed upon the dried outer sur- 
face of the bladder, the powder will disappear in the course of a few hours, 
and the usual reactions will show the presence of lime and phosphate of 
lime in the fluid. 

Of course the passage of the carbonate and phosphate of lime in the 



MANNER IN WmCH ROOTS TAKE UP FOOD. 107 

stances held in solution by the Avater moving about in 
the soil may not, under certain circumstances, be ab- 
sorbed by the roots of the plants. But it is based upon 
the assumed tact, that the roots receive their food from 
the thin layer of water which, retained by cajiillary 
attraction, is in intimate contact with the eartli and 
with the root surface, and not from more remote layers 
of water ; that between the root surface, the layer of 
water, and the earthy particles, a reciprocal action goes 
on, which docs not take place between the water and 
the earthy particles alone. It also assumes as proba- 
ble, that the nutritive substances adhering, in a state 
of exceedingly minute division, to the outer surface of 
the earthy particles, are in direct contact with the fluid 
of the porous absorbent cell-walls, by means of a very 
thin layer of water ; and that the solution of the solid 
elements is eftected in the pores of the cell-walls, 
whence they pass immediately into the system of the 
plant. 

The facts in support of this view, briefly recapitu- 
lated, are as follow : Tlie roots of all land-plants, and 
of most marsh-plants, are in direct contact with the 
earthy particles. These particles of earth have the 
power of attracting the most important elements of 
food conveyed to them in watery solution (such as pot- 
ash, phosphoric acid, siUcic acid, ammonia), and of re- 
taining them, just as charcoal retains colouring matters. 
In most cases that have been investigated it has been 
found that the M'ater moving about in the ground ex- 
tracts from the soil scarcely any appreciable quantities 
of ammonia, no phosphoric acid, and potash in such 
trifling quantities, that all these together are quite in- 
sufficient to afford the requisite supply of these ele- 
ments to the plants growing in the field. 

solid state tlirough the bladder into the water, is only apparent. Both 
salts are dissolved in the pores of the membrane where they come in con- 
tact with the acidulated water, and as the evaporation of the water from 
the bladder somewhat diminishes the inner pressure as compared to the 
outer, the stronger outer pressure, assisted by the solvent power of the 
water, forces the solution inward. 



108 THE SOIL. 

"Water stagnant in the gronnd, so far from promot- 
ing the absorption of food, injures the growth of land- 
plants. 

If plants really did receive the elements of their 
food from a solution which could change its place in 
the soil, then all drainage waters, spring, brook, and 
river waters, must contain the principal nutritive sub- 
stances of all plants ; and it must be quite practicable, 
by continued lixiviation, to extract from every arable 
soil, without distinction, all the nutritive substances, 
either entirely, or at least in amount corresponding to 
the quantity contained in a crop. But, in reality, this 
is not practicable. By the action of water, the field 
loses none of the principal conditions of its fertility, in 
such a degree as perceptibly to impair the growth of 
plants cultivated on it. 

For thousands of years, all fields have been exposed 
to the lixiviating action of rain-water, without losing 
their powers of fertility. In all parts of the earth, 
where man for the first time draws furrows wdth the 
plough, he finds the arable crust, or top layer of the 
field, richer and more fertile than the subsoil. The fer- 
tility of the ground is not diminished by plants grow- 
ing thereon ; not until the i)lants are removed from the 
ground does it 2:radually lose its fruitfulness. 

The opinion that some cause is at work within the 
plant itself, which seems to render soluble certain ele- 
ments of food, and make them available for nutrition, is 
not contradicted by the experiments of Knop, Sachs, 
and Stohmann, who have shown that many land-plants, 
without touching a particle of earth, may be brought 
to flowering and seed-bearing in water, to which the 
mineral elements of food have been added. These ex- 
periments, which have thrown considerable light upon 
the physiological importance of the several nutritive 
substances (see Appendix E.), merely prove how ad- 
mirably the ground is adapted to the requirements of 
plants, and how much human ingenuity, knowledge, 
and minute care, it takes to supply, under circum- 
stances difi'ering so widely from the natural condition, 



PLANTS GEOWN IN SOIL AND IN WATER. 109 

certain properties of arable soil, wliicli insure the 
healtliy ij:rowth of plants. 

If the supply of nutritive substances in a state of 
solution were really suited to the nature of the plant 
and the functions of the roots, it would follow that in 
such a solution, most abundantly provided with all the 
elements of food in the most movable form, the plants 
must thrive the more luxuriantly the fewer the obsta- 
cles are which oppose their absorption of food. 

A youniz; rye-plant, placed in a fertile soil, will 
often send forth a bunch of thirty or forty stalks, each 
of them bearing an ear, and will yield a thousandfold 
crop of grains, or even more ; yet this plant draws its 
mineral food from a volume of earth, from which the 
most persevering lixiviation with pure water, or water 
containing carbonic acid, will not extract even the one- 
hundredth part of the phosphoric acid and nitrogen, 
nor the fiftieth part of the potash and the silicic acid, 
which the plant has drawn from the soil. How is it 
then possible, under such circumstances, to assume that 
water alone would have sufficed, by virtue of its solvent 
power, to render available to the plant all the sub- 
stances found in it ? 

None of the plants grown in watery solutions of the 
mineral elements of their food, even though thriving 
luxuriantly, will bear the remotest comparison, in the 
bulk of vegetable matter produced, with plants grown 
in a fertile soil ; and the entire process of developement 
in them proves that the conditions of thriving growth 
in the soil are quite of another kind. 

The greatest weight of crop obtained by Stohmann 
from an Indian corn plant grown in water amounted to 
84 grammes ; while he obtained from another Indian 
corn plant grown in the soil, at the same time and from 
the same seed, a crop weighing 346 grammes. In KnopV 
experiments, the dry weight of two Indian corn plants, 
the one grown in water, the other in the soil, was found 
to be as 1 : 7. 

The water circulating in the soil contains chloride 
of sodium, lime, and magnesia — the two latter in com- 



110 THE SOIL. 

bination partly with carbonic acid, partly with mineral 
acids ; and there can hardly be a doubt but that the 
plant absorbs a portion of these substances from the 
solution. The same must apply equally to potash, 
ammonia, and the dissolved phosphates ; but the water 
circulating in the soil, in a normal condition, either does 
not hold the three last-named substances in solution, or 
not in sufficient quantities to suj)ply the demands of 
the plant. 

According to the ordinary rules of natural science, 
when wc seek to explain a phenomenon, we leave out 
of view those cases in which the conditions superinduc- 
ing the phenomenon are clear and patent. For in- 
stance, if we find in bog-water all the ash-constituents 
of duckweed, there can be no doubt about the form in 
which they passed into the plant ; they were dissolved 
in water, and they were absorbed in a soluble state. 
In such a case, we have merely to explain the reason 
why the several ash-constituents, being all present in 
one and the same form, have yet passed into the plant 
in unequal proportions. 

If, in another case, we find that the rain-water 
which falls on a given area of land, dissolves out of the 
soil many times more potash than was contained in a 
crop of turnijjs grown on that area, there is every rea- 
son to assume tliat the turnip, like the duckweed, has 
absorbed the needful potash from a solution. But, if 
in the entire quantity of water which falls on the field 
during the period of vegetation, we find only just so 
much potash as the turnip crop requires, and no more, 
the assumption that the potash in the turnips has been 
derived from this solution would necessarily involve 
the impossible supposition, that all the watery particles 
containing potash must have been in contact with the 
coots of the turnips ; otherwise, the latter could not 
have absorbed so much potash as is actually found in 
them. This supposition is impossible ; because, during 
the time when the turnip vegetates, there is generally 
no water circulating in the soil — such, for instance, as 
might be carried off by drain-pipes. 



IN WHAT MANNER PLANTS ABSORB FOOD. Ill 

If the examination of tlie water in the soil sliows it 
to contain lialf the quantity of potash required by a 
turnip crop, there is no need to explain how the dis- 
solved half of the potash has passed into the turnip- 
plant, but in what form and manner the plant has ab- 
sorbed the other half deficient in the water. 

If, again, by the examination of the water in other 
fields, we find that it contains only ^ ; nay, only -J, -^\, 
or 5V o^' the quantity of potasli found in a turnip crop 
grown upon it ; and if we further ascertain that in a 
soil, favourable for tlie growth of turnips, the pLant 
always takes up the same quantity of potash from the 
ground, no matter how much or how little of that sub- 
stance the water circulating in the soil dissolves from 
the earth ; it follows, that as the water, the soil, and the 
plant, can alone come into consideration here, the direct 
power of the water to dissolve potash is of no impor- 
tance to the plant ; and that tlie plant itself, by the 
help of water, must have rendered the needful potash 
soluble. 

What is here asserted of one constituent, holds good 
for all. If, therefore, we find, that by treating a soil 
with rain-water we can dissolve from it potash, phos- 
phoric acid, and ammonia or nitric acid, in suflicient 
quantity to account for the presence of these substances 
in the cereal plants grown on such a soil ; while, on the 
other hand, we find that the ])lant contains a hundred 
times more silicic acid than the water could possibly 
have supplied ; the cause of the absorption of silicic 
acid, which clearly is not in the water, must again here 
be souglit for in the plant itself. Again, if other cases 
show that an equally abundant crop of corn is obtained 
on fields, from which water fails to extract phosphoric 
acid or ammonia, here, too, we are led to the conclusion 
that the nutritive substances dissolved in the water are 
of no special importance to the plants in question ; but 
that, as an indispensable requisite, these elements must 
])0ssess the foi-m most suitable for the action of tlie root, 
be this what it may. 

Tlie beautiful experiments on vegetation made con- 



112 THE SOIL. 

jointly by Professor Niigeli and Dr. Zoeller, in the 
Botanic Garden at Munich, most strikingly prove the 
correctness of the conclusions to which the analysis of 
drainage and other waters has led. Instead of growing 
plants in solutions of the mineral elements of their food, 
as had been done in all previous experiments, they pur- 
sued the very opposite course ; they placed the seeds 
of the plants in a soil containing all the elements of 
their food in an insoluble state. 

In such experiments, it is not easy to find a material 
which can be used as a substitute for arable soil, and 
possessing all its properties ; and the difficulty is proved 
by the fact, that none of the plants grown by Boussin- 
gault and others, in an artificial soil, abundantly pro- 
vided with all tlie elements of food, could even remotely 
bear comparison with a plant grown in a fertile arable 
soil. Pulverised charcoal or pumice-stone have the 
power of extracting many elements of the food of plants 
from their solutions, and physically fixing them ; but 
they have not, in the moist state, that soft, plastic, and 
yielding condition of the clay in arable soil, which per- 
mits the intimate contact of the roots with the earthy 
particles. The best substitute for the purpose is coarse- 
ly-powdered turf, which, in the moist state, forms a 
plastic mass, bearing a remote resemblance to clay, and, 
like arable soil, absorbs all elements of the food of 
plants from their solutions. Accordingly Nageli and 
Zoeller used in their experiments coarsely-powdered 
turf as the vehicle of the nutritive substances, after hav- 
ing ascertained its absorptive power for the several ele- 
ments of food. 

A litre (1*76 pint) of turf, weighing 324 grammes 
(4987*6 grs.), was found to absorb from solutions of car- 
bonate of potash, carbonate of ammonia, carbonate of 
soda, and phosphate of lime — 1'45 grammes (22*4 grs.) 
of potash, 1-227 grammes (19 grs.) of ammonia, 0'205 
gramme (3'2 grs.) of soda, and 0-890 gramme (13*7 grs.) 
of phosphate of lime equal to 0"410 gramme (6*3 grs.) 
of phosphoric acid. 

The quantities of potash and ammonia here given do 



ABSORPTIVE rOWER OF TURF. 113 

not show the total amounts of these substances uhicli 
the turf will ahsoi'b to the point of complete saturation, 
but merely what it will take up when sin)ply mixed 
with the solutions, and left in contact with them for a 
few hours. If we add more of these solutions to the 
turf-})()wder, the fluid exhibits an alkaline reaction, 
which disappears again after one or more days ; and it 
is only at the end of eight days, when the litre (1*76 
pint) of turf has taken u]) 7'892 grammes (121-G grs.) of 
potash and 1:*160 grammes (G4-2 grs.) of ammonia, that 
the alkaline reaction remains i3ermanent. What we 
shall hereafter designate as saturated turf contains 
only 1 of the potash and ^ of the ammonia, which 
would be absorbed by that substance to the point of 
complete saturation. 

To represent different soils, containing various pro- 
portions of nutritive substances, three mixtures were 
made of saturated and ordinary turf-powder: — ■ 

1 mixture contained 1 vol. of saturated turf-powder, 

2 " 1 '■ '■ and 1 vol. of dry turf-powder, 
a ■ " 1 " " '"3 

These mixtures represented different kinds of earth, in 
each volume of which the third contained one-fourth, 
the second one-half the quantity of the nutritive sub- 
stances present in the first. 

The pure turf contained 2*5 per cent, of nitrogen, 
and 100 grammes yielded 4*4 grammes of ash, which, 
upon analysis, were found to contain 0"115 gramme of 
potash, 0'0576 gramme of phosphoric acid, besides lime, 
sesquioxide of iron, silicic acid, magnesia, sulphuric 
acid, and soda. (See more fully in Appendix E.) 

"With each of these mixtures a pot was filled, each 
pot holding S^ litres (2592 grammes, = 39917 grs.) ; a 
fourth pot, of similar size, contained dry turf-powder. 

Taking into consideration the amount of ash in 
ordinary turf, the four pots severally contained the fol- 
lowing quantities of nutritive substances : — 



114 



THE SOIL. 



Nitrogen 
Potash . 
Phosphoric 
acid 



ic ) 



1st Pot, 

■with common 

turf. 



Grams. Grains. 

71- =1093-5 

3-18 = 49-0 

1-586=: 24-4 



2d Pot, 

quarter saturated 

turf. 



Grams. Grains. 
2-60 =40-0 
3-075=47-4 

0-83 =12-8 



3d Pot, 

half saturated 

turf. 



4th Pot, 

fully saturated 

turf. 



Grams. Grains. 
4-32=66-5 
6-15=94-7 

1-75 = 27-0 



Grams. Grains. 

8-65 = 133-2 

12-30 = 189-5 

3-49= 53-8 



The figures showing the quantities of nitrogen, pot- 
ash, and phosphoric acid, express the amount of nitro- 
gen in the dry turf (in the first pot), and the amount of 
potash and phosphoric acid in its ash. For the other 
pots, the figures express the quantity of nutritive sub- 
stances which had been added. 

In each of these pots, five dwarf-beans were planted, 
the weight of which had been carefully determined, and 
which had been allowed to germinate in pure water. 

The plants in the three manured pots grew very 
evenly, and the luxuriance of their growth excited the 
astonishment of all Avho saw them. 

During the first month, the plants in pots 2 and 3 
(filled respectively with turf ^ and ^ saturated) pre- 
sented a finer appearance than the others ; but those in 
pot 4 (filled with saturated turf) soon overtook them ; 
and the difference in the size of the leaves, in propor- 
tion to the greater richness of the soil, was very 
striking. 

Kemarkable, too, was the influence of the soil upon 
the term of the vegetating period. Each of the five 
plants in the pure turf produced a small pod, and, to- 
gether, the five pods contained 14 seeds. During the 
ripening of the seeds, tlie leaves died from below up- 
wards ; so that, before the pods had turned yellow, all 
the leaves had fallen ofi". The plants in the saturated 
turf remained green longer than any of the others, and 
their seeds ripened latest. The last pod of these plants 
was cropped on July 29, whilst the last pod of the 
plants in the pure turf had already been cropped on 
July 16. 



GROWTH OF BEANS IN EXPERIMENTAL SOIL, 



115 



The followiug table sliows the crops yielded by all 
four pots, with the number and weight of the seeds : — 





1st Pot, 
pure turf. 


2d Pot, 

turf quarter 

saturated. 


Sd Pot, 
turf half 
saturated. 


4th Pot, 
turf fully 
saturated. 


Number gathered. . . . 
" sown 

Gathered 

Sowii 


Beans. 

U 

5 

Grammes. 
7-9 
3-965 


Beans. 

79 

5 

Weight in 
Grammes. 
56-7 

3-88 


Beans. 

80 

5 

Grammes. 
Grammes. 
7-1-3 

4-087 


Beans. 

103 
5 

Grammes. 
105- 
4-055 






Excess of crop over } 
seed j' 


3-9 


52-82 


70-213 


100-945 



What strikes us here at once is the great difference 
in tlie number and weight of the seeds respectively 
gathered from the several pots. The soil richer in 
nutritive substances yielded not only more, but larger 
and heavier seeds, the averas^e weio-ht in millirjrammes 
being respectively : — 





1st Pot. 


2d Pot. 


3d Pot. 


4th Pot. 


One secd-bcan weighed 


milligr. 
793 
564 


, milligr. 
' 776 
718 


milligr. 
817 
917 


milligr. 
813 


One of the gathered beans 


weighed. . 


1019 



Of the seeds of the plants grown in the first pot 
(pure turf), seven weighed no more than five of the 
beans originally sown ; whereas those of the i-)lants 
grown in the saturated turf weighed each l-5th more 
than one of the seed-beans. 

If we compare the crop of seeds with the quantity 
of nutritive substances contained in the turf of the four 
pots, we see at once what influence the form and distri- 
bution of the nutritive substances have exercised upon 
their nutritive power. 



116 



THE SOIL. 



The l-4th saturated turf contained a little above 
one-half (0*83 gramme) more phosphoric acid than that 
in the pure turf (1*586 grammes) ; the potash was 
doubled ; and the amount of nitrogen was increased 
only by aV^^^- The crop, however, exceeded that ob- 
tained from the plants grown in pure turf, not by ^d 
(corresponding to the quantity of phosphoric acid 
added), but it "was thirteen times as large. The feeble 
manuring had caused the turf in the second pot to ren- 
der thirteen times more nutritive matter for the forma- 
tion of seed alone, and for the entire plants about thirty 
times more than the pure turf. 

It is evident that only a small proportion of the ash- 
constituents in the pure turf were present in a form 
suitable for the nutrition of the bean-plant. They could 
not be absorbed, because they were in chemi(;al combi- 
nation in the substance of the turf. To use a somewhat 
imperfect figure, the nutritive elements in the pure turf 
may be imagined to be surrounded by the turfy sub- 
stance, which hinders their contact with the roots ; 
while in tlie saturated turf these elements form the 
outer coating of the turfy substance. 

The crops of seeds show further that they were not 
in proportion to the nutritive substances contained in 
the soil, but that the poorer mixture yielded far more 
seeds than it should have done in proportion to the 
production of the richer mixtures. The proportions in 
the several mixtures were as follows : — 





2d Pot, 
quar. saturated. 


Sd Pot, 
half saturated. 


4th Pot, 
fully saturated. 


Amount of manure 

Crop gathered, as 


1 
2 


2 
2-8 


4 
4 



It is not difficult to understand why this should be 
so. The fact that the ^-saturated turf yielded twice as 
much crop as corresponded to the amount of manure, 
proves that the absorbent root-surface had come in con- 
tact with double the number of nutritive turf particles. 



RELATION OF CROP TO FOOD IN SOIL, 117 

According to weight, the ^-saturated turf contained, in 
every cubic centimetre, only ^th of the nutritive sub- 
stances found in the completely saturated turf; but, by 
mixing 1 volume of saturated with 3 volumes of unsat- 
urated turf, the former had become far more distrib- 
uted, and its volume or ethcient surface had been made 
larger. Supposing it were possible to coat 3 volumes 
of ordinary turf-powder with 1 volume of saturated, so 
as completely to surround every fragment of the former 
with saturated turf particles, the bean-plants would, in 
a soil so prepared, grow as luxuriantly as if every par- 
ticle of the turf were thoroughly saturated with nutri- 
tive substances. 

Hence, the higher produce obtained from the com- 
paratively poorer soil proves that it is only the surface 
of the soil, containing the nutritive elements, which is 
elieciive ; that the fertility of a soil is not proportionate 
to the quantity of nutritive substances wliich chemical 
analysis proves to be present ; and lastly, these facts 
show that it is not water which, by virtue of its solvent 
power, has made the nutritive elements available to the 
roots. 

"We know by experiment, that when, water has dis- 
solved from a saturated soil a certain quantity of am- 
monia, potash, &c., the same amount of water will not 
further dissolve from a half-saturated soil (or a soil from 
which one-half of the absorbed potash and ammonia has 
already been extracted) half so much as from the sat- 
urated soil ; but that the earth, in proportion as it has 
thus become poorer in nutritive substances, will all the 
more hrmly retain the residue of the ingredients ab- 
sorbed by it. 

In the half-saturated turf the nutritive elements are 
much more lirnd}^ bound than in the fully saturated ; 
and, again, in the quarter-saturated much more iirmly 
than in the half-saturated. 

Hence, even if the water had been able to dissolve 
and convey to the roots half as much from the half- 
saturated as from the fully saturated, and half as much 
from the quarter-saturated as from the half-saturated, 



118 THE SOIL. 

still the produce could not in any case be greater than 
in proportion to the amonnt of nutritive substances in 
the soil. But, in fact, they were far greater, and the 
roots actually absorbed more nutritive substances than 
the water could possibly have conveyed to them, even 
under the most favourable circumstances. 

These experiments liave, for the first time, afforded 
direct proof that plants possess the power of absorbing 
their necessary nutritive elements ft'om a soil in which 
they are present in physical combination, i.e. in a state 
wherein they have lost their solubility in water ; and 
the comportment of arable and cultivated soil in general 
shows that the nutritive substances contained in them 
must be present in the same form as in the artificial 
turf soil of these experiments, with this difference, how- 
ever, that the earthy particles in the arable soil are 
not merely the vehicles of these substances, but their 
source. In a soil consisting of turf-powder, a second 
crop will not succeed so well as the first, unless the 
nutritive substances which have been removed are 
again supplied ; nor will the soil regain its fertility, 
however long it be left fallow. 

The benefit derived from mechanical tillage of the 
ground depends upon the law, tliat the nutritive sub- 
stances existing in a fruitful soil are not made to change 
their place by the water circulating in it ; that the cul- 
tivated plants receive their food principally from the 
earthy particles with which the roots are in direct con- 
tact, out of a solution forming around the roots them- 
selves ; and that all nutritive substances lying beyond 
the immediate reach of the roots, though in themselves 
quite effective as food, are not directly available for the 
use of the plants. 

There are no isolated laws in nature, but they are 
all together links in one chain of laws, which are in 
turn subordinate to a higher and a highest law. 

With the natural law, that organic life is developed 
only in the outermost crust of the earth which is ex- 
posed to the sun, is most intimately connected the 
power of the fragments of that crust which form the 



FIXICD STATE OF FOOD OF PLANTS IN THE SOIL. 119 

arable surface soil, to collect and retain all those nutri- 
tive substances on wliicli life deiJcnds. A plant is not, 
like an animal, endowed with special organs to dissolve 
the food and make it ready for absorption ; this prep- 
aration of the nutriment is assigned by another law to 
the fruitful earth itself, which in this respect discharges 
the functions performed by the stomach and intestines 
of animals. The arable soil decomposes all salts of 
potash, of ammonia, and the soluble phosphates ; and 
the potash, ammonia, and phosphoric acid always take 
the same form in the soil, no matter from what salt 
they are derived. In performing this function, the 
plant-bearing earth constitutes for the use of man and 
beast an immense purifying apparatus, whereby it 
removes from the water all matters hurtful to the 
health of animals, and all products resulting from the 
decay and putrefaction of deceased generations of plants 
and animals. 

The question how much of the several nutritive sub- 
stances a soil must contain to yield remunerative crops 
is of great importance, but its exact determination is 
beset with vast difficulties. If, indeed, the nutritive 
power of an arable soil depends upon the quantity of 
substances held in physical combination in the ground, 
it is evident that a chemical analysis, which cannot 
rigorously distinguish elements in chemical combina- 
tion from those in physical combination, must fail to 
afibrd any certain conclusion in the matter. 

In comparing several equally productive soils, we 
often find that they differ immensely in their chemical 
comj^osition ; and that of two soils containing, the one 80 
to 90 per cent., the other only 20 per cent, of pebbles 
and sand, the former wall frequently yield better crops 
than the latter. The case is possible, that a soil fruitful 
in itself may not suffer any diminution of its fertility by 
being mixed with half its volume of sand, but may 
actually become more productive, though it now^ con- 
tains, in every part of its transverse section, one-third 
less nutritive matter than before. The reason is, that 
by the addition of sand the food-affording sm-face of the 



120 



THE SOIL, 



other constituent parts of the soil is enlarged, and on 
this everything depends as regards the power of the soil 
to give up to plants the food contained in it. 

A soil on wliicli lye thrives well often ])roves un- 
suited for the profitable cultivation of wheat, though 
both plants take from the soil exactly the same con- 
stituents. 

It is clear that the failure of wheat on such a soil 
arises from this cause, that the wheat plants, within the 
allotted period of their existence, do not find nutriment 
enough for their full developement in the food-supplying 
soil about their roots, whilst the quantity supplied is 
ample for the rye plants. 

JSTow chemical analysis proves that such a rye soil 
altogether contains, to a depth of 5 to 10 inches, fifty — 
nay, a hundred times more of the food-elements of the 
wheat plant than would be required for an abundant 
crop of wheat ; and yet, in spite of this superabundance, 
the field will afford no remunerative crop to the agri- 
culturist. 

If we compare tlie quantities of phosphoric acid and 
potash drawn from an area of 2^- acres (hectare), by an 
average wheat crop (2000 kilogramines=MOO lbs. of 
grain, and 5000 kilogrammes= 11000 lbs. of straw) and 
a rye crop (1600 kilogrammes =3520 lbs. of grain and 
3800 kilogrammes =8360 lbs. of straw), we find that 
the two crops severally received from the soil — 





Wheat. 


Rye. 


Phosphoric acid 

Potash 

Silicic acid 


Kilogr. lbs. lbs. 
25—26= 65 to 57 
52 = 114 
160=352 


Kilogr. lbs. lbs. 

17— 18= 37 to 39 

39— 40= 86— 88 

100—110=220—242 



The difference in the absolute requirement is there- 
fore very small. The wheat crop received from the soil 
only 9 kilogrammes (=20 lbs.) of phosphoric acid, about 
12 kilogrammes (=264 lbs.) of potash, and 50 to 60 



WHY KYE MAY FLOUKISII AND KOT "SVIIKAT. 121 

kilogrammes (=110 to 132 lbs.) of silicic acid, more 
than the rye crop. 

Uefore the true cause M'as known upon which the 
nutritive power of arable soil depends, it was utterly 
incomprehensible how this triHing- difference of a few 
pounds of phosphoric acid, silicic ac!d, and potash in 
the recpiirements of wheat and rye, could make so great 
a difference in the quality of a field ; for in comparison 
with the total amount of these ingredients actually con- 
tained in the rye field, the additional quantity required 
by the wheat plant is inappreciably small. 

This difference would indeed be inconceivable if the 
nutritive substances required by the cereal plants had 
any perceptible power of locomotion, for in that case 
there could not bo an actual deficiency of food in any 
given spot of the soil ; every fall of rain would provide 
the poorer places with nutriment, if the trifling excess 
required by the wheat above the rye could really be 
distributed by the agency of water. 

Thus, although a soil suited for rye but not for 
wheat, may contain, within a short distance from the 
roots of the wheat, a large quantity of phosplioric acid 
and potash, often amounting, in the vohime of earth 
between two rye plants, to fifty times more than the 
trifling addition demanded by the wheat, yet, in point 
of fact, this nutriment camiot reach the roots of the 
latter. 

But if we consider that the nutritive substances can- 
not of themselves change their place in the ground, the 
failure of wheat upon a rye field is very simply ex- 
plained. 

If a 2^- acre field yields to an average rye crop 
(grain and straw) 17 million milligrammes (=:37*-l lbs.) 
of ])l!osphoric acid, 39 million milligrames (=85'8 
lbs.) of potash, and 102 million milligrammes {=224:-4: 
grains) of silicic acid, then the rye plants growing on a 
square decimetre (=:15'3 square inches) receive from 
the soil 17 milligrammes ( = 0*26 grains) of phosphoric 
acid, 30 milligrammes (=0'G grain) of potash, and 102 
milligrammes (=1-5G grains) of silicic acid. 

G 



122 THE SOIL. 

Now, from the same area of a good wheat soil, the 
wheat plants growing on it receive 26 milligrammes of 
phosphoric acid, 52 milligrammes of potash, and IGO 
milligrammes of silicic acid. The food-absorbent sur- 
face of the rye and wheat plants is not in contact with 
all the earthy particles which contain food in a square 
decimetre of the field downwards, but only with a small 
volume of the soil ; and it is quite evident, that if the 
seed is to thrive in every spot, the earthy particles, 
which do not happen to come in contact with the roots, 
must contain as much nutritive matter as the others. 

If we could ascertain with any certainty the root- 
surface which absorbs nutriment, we might infer the 
volume of earth from which it received food, for every 
root-fibre is surrounded by a cylinder of earth, the inner 
wall of which facing the root is as it were gnawed off by 
the extremities of the root which press downwards, or 
by the cell-surfaces which are deposited in a downward 
direction. But in no plant are the diameter and length 
of the root-fibres determined, and we must rest satisfied 
with an approximative estimation. 

Let us assume that the 17 milligrammes (=0'26 gr.) 
of phoshporic acid, 39 milligrammes (=0'6 gr.) of pot- 
ash, and 102 milligrammes (=1'56 grs.) of silicic acid, 
are absorbed from a mass of earth the transverse sec- 
tion of which is 100 square millimetres (=15"3 square 
inches), then the rye-field in each square decimetre 
(10,000 square millimetres) will contain 1700 milli- 
grammes ( = 26 '2 grs.) of phosphoric acid, 3900 milli- 
grammes ( = 60 grs.) of potash, and 10,200 milli- 
grammes ( = 15*7 gi's.) of silicic acid ; that is, a hun- 
dred times as much as an average rye crop requires. 
Now, as the wheat plant, to tlirive equally well, must 
receive half as much again of phosj)horic and silicic 
acid, and 0'4 more potash, from the same portions of 
the soil, it follows that if a hectare (2^ acres), to produce 
an average rye crop, contains 

1700 kilogrammes = 3740 lbs. of phosphoric acid, 
3900 " = 8580 " potash, and 

10200 " = 22440 " silicic acid. 



ESTIMATION OF FOOD IN A WHEAT SOIL. 123 

a fertile wheat soil must contain 

2560 kilogrammes = 6632 lbs. of pliosphoric acid, 
5200 " = 11440 " potash, and 

15300 " = 33G60 " silicic acid, 

If a cubic decimetre (1 litre = 1*7 pint) of arable 
soil weighs on an average 1200 grammes ( = 2*G4 lbs.), 
and we assume that the greater number of the roots of 
a wheat plant do not go deeper than 25 centimetres (10 
inches), then the above 1700 milligrammes of phos- 
phoric acid, 3900 milligrammes of potash, and 10,200 
milligrammes of silicic acid, must be contained in an 
aj'ailable form in 2.V cubic decimetres, or 3000 grammes 
( z= G6 ll)s.) of soil : tliis makes 0-05G per cent, of phos- 
phoric acid, 0'034: per cent, of potash, and 0-31: per 
cent, of silicic acid. 

Before we discuss the inferences which follow from 
these numbers, we must remember that they involve 
some hypothetical elements, which ought not to be left 
out of view. The numbers representing the quantity 
of ash constituents, which an average rye and wheat 
crop take from a hectare (2^ acres) in corn and straw, 
have been determined by chemical analysis, and are 
not hypothetical. It is therefore certain that a wheat 
crop draws from the ground half as much again of 
phosphoric acid and silicic acid, and one-third more 
potash, than a rye crop. 

The supposition that a wheat soil, to the depth of 
10 inches, contains in physical combination 0.056 per 
cent, of phosphoric acid, 0"034: per cent, of potash, and 
0'31: per cent, of silicic acid, which makes a hundred 
times as much as a wheat crop would take in corn and 
straw from the field, is purely hypothetical ; and the 
present question is to determine the limits up to which 
this estimate may be accepted as true. 

If arable soil is left for twenty-four hours in contact 
with cold muriatic acid, a certain quantity of potash, 
phosphoric acid, silicic acid, as well as lime, magnesia, 
<fec. is extracted. If the soil is treated for a long time 
with boiling muriatic acid, the quantities of dissolved 
silicic acid and potash are much greater. Lastly, by 



124 



THE SOIL. 



decomposing by fusion the silicates, and then treating 
with hot muriatic acid, we can obtain all the potash 
and silicic acid contained in the soil. Without risk of 
error ^ve may assume that those nutritive substances 
which can be extracted by cold muriatic acid are most 
feebly retained by the soil, and approach nearest the 
elements in physical combination ; or, at all events, so 
near, that by the common disintegrating agencies they 
very easily pass into this form of combination. 

In this way Dr. Zoeller subjected to analysis two 
kinds of wheat soil — the loam of Bogenhausen and of 
Weihenstephan, the latter of which in particular repre- 
sents an excellent wheat soil. One hundred parts ot 
these two soils yielded to cold muriatic acid — 





Phosphoric acid. 


Potash. 


Silicic acid. 


Soil of Weihenstephan 

Soil of Bogeubauseii 


0-219 
0-129 


0249 
0-093 


0-596 
0-674 



If these quantities of nutritive elements are present 
in an available condition in these soils, that of Weihen- 
stephan would contain of phosphoric acid almost 400 
times, of potash TOO times, and of silicic acid rather 
more than 190 times, as much as a wheat crop re- 
quires : in the soil of Bogenhausen the amount of phos- 
phoric acid, potash, and silicic acid would be twice as 
large as the hypothesis presupposed. 

The well-known analyses of similar soils by other 
chemists show that the assumed estimate of the nutri- 
tive substances required in a good wheat or rye soil is 
rather below than above the actual amount ; and, in 
fact, the future prospects of agriculture would be very 
gloomy, if the ground was not far richer in nutritive 
substances than has here been hypothetically assumed. 

This is, perhaps, the place to state the distinction 
between the fertility of a field and its ]3roductive pow- 
ers. According to the experiments of ISTageli and Zoel- 
ler, mentioned above, the turf maybe so saturated with 
the necessary nutritive substances as to become an ex- 



NATURE OF A RYE SOIL. 125 

tremely fruitlul soil for beans ; and a comparison of 
the ash constituents, in the stalks and seeds of the crop, 
with the quantity which had been added to the turf, 
shows that the twelve to fourteen-fold quantity of these 
ash constituents was enough to produce a very abun- 
dant seed crop. The porous turf, saturated e\en in 
its minutest particles with nutritive elements, favoured 
in this case an enormous developement of the roots, to 
which the largeness of the crops is due. Nothiug can 
be more certain than that its power of production 
measured by time is very small, and that after a very 
few harvests its fertility would vanish speedily and for 
ever. 

That our corn fields should contain nutritive sub- 
stances in very great abundance is the necessary condi- 
tion for a continuance of good crops, but it is not indis- 
pensable for 0716 rich harvest. 

A good rye soil is one which produces an average 
rye crop, but less than an average wheat crop. 

From what we have seen, the reason why a wheat 
plant, which requires from the soil the same elements 
as the rye plant, will not thrive as well as the latter 
upon a rye soil, is founded on this, that during the 
same period of time the wheat needs more of these nu- 
tritive substances than the rye, but cannot obtain this 
additional quantity. Hence, a good wheat soil which 
yields an average wheat crop, differs from a good rye 
soil Avhich produces an average rye crop, inasmuch as 
the wheat soil in all its parts contains more nutritive 
substances, just in proportion as the wheat crop needs 
and carries away more than the rye crop. 

A good rye soil, which is able to give and does give 
1 per cent, of its nutritive substances to an average rye 
crop, would necessarily yield an average wheat crop, if 
the wheat plants growing upon it could extract 1^ per 
cent, of its nutriment. But, in fact, this does not take 
place : wlumce it follows that the absorbent root-sur- 
faces of the wheat cannot be half as large again as 
those of the rje ; for, were this the case, the roots of 
the wheat would come into contact with half as many 



126 THE SOIL. 

more earthy particles yielding nutriment, i, e. the rye 
soil would necessarily produce an average wheat crop, 
which however is not the case. 

The comparative returns, in corn and straw, from a 
rye soil, which has been sown simultaneously half with 
wheat and half with rye, might therefore enable us to 
estimate the extent of root surface in wheat and rye 
plants. If the wheat crop from one-half of such a 
field, reckoning by the hectare, receives as much phos- 
phoric acid and potash as the rye crop from the other 
half (17 kilogrammes of phosphoric acid and 39 kilo- 
grammes of potash), this would argue that the roots of 
the wheat have cotne in contact with earth yielding as 
much nutritive substance, and the earth with the same 
extent of absorbent root surfaces, as in the case of the 
rye. If the wheat crop contains phosphoric acid, pot- 
ash, and silicic acid, either more or less than the rye 
croj), this would lead us to infer a larger or smaller 
ramification of the roots. Experiments of this kind 
with rye, wheat, barley, and oats are well worth mak- 
ing, although they have no practical interest for the 
farmer, but merely a physiological importance, and 
would finally lead to conclusions, the correctness of 
which lies within rather wide limits. The absorptive 
power of the plant, and the time of absorption, make a 
diiference which, however, hereby becomes perceptible. 

Of two plants, with the same absorbent root surface, 
and yielding equal produce, one of which flowers and 
ripens earlier than the other, the one with the shorter 
period of vegetation nmst find somewhat more food, in 
all the places which furnish its nutriment, in order to 
receive the same amount as the other, which has a 
longer time for absorption. 

Thus, the only hypothetical assumptions in deter- 
mining the above numbers are, that the food-absorbent 
root surfaces of rye and wheat are equal, and that the 
rye soil yields neither more nor less than exactly 1 per 
cent, of its nutritive substances. No doubt such a soil 
has no actual existence ; but, supposing that we had 
such a soil before us, and were to put the question how 



CONVERSION OF KTE INTO WnEAT SOIL. 



127 



much nutriment we must add to convert it into a per- 
manently productive wheat soil, the answer would be 
not hypothetical, but perfectly trustworthy and exact. 
If 



Phosphoric acid. 



Potash. 



Silicic acid. 



The wheat soil contains 

The rye soil 

The wheat soil is the richer of ) 
the two by J 



Kilogr. 
2560 
1700 

860 



Kilogr. 
5200 
3900 

1300 



Kilogr. 
15300 
10200 

5100 



Hence, to a rye soil of a given condition and productive 
power, we should have to add, in some form or other, 
one-half more phosphoric and silicic acid, and one-third 
more potash, than it already contains, to make it capa- 
ble of producing average crops of wheat grain and 
straw. 

And to obtain permanently from a wheat soil a 
crop half as large again as an average harvest, we 
should add one-half more of nutritive substances than 
it already contains. 





Phosphoric acid. 


Potash. 


Silicic acid. 


A hectare of wheat soil contains 
One-half more 


Kilogr. 
2560 
1280 

3840 


Kilogr. 
5200 
2600 

7800 


Kilogr. 

10200 

5100 






» 


15300 



These speculations have no other object than to 
Bhow that a small difference in the absolute quantity of 
a nutritive element, required by one kind of plant more 
than by another, presupposes a great excess in the 
amount of this constituent in the soil, A wheat crop 
takes from the soil, per hectare (2^ acres), only 8"G kil- 
ogrammes (19 lbs.) more phosj)lioric acid than a rye 
crop ; but that the wheat-roots may appropriate these 
S'Q kilogrammes, the soil must contain a hundred times 



128 THE SOIL. 

as much (860 kilogrammes) of phosphoric acid as the 
rye soil, or perhaps even more. 

Although these figures refer to an ideal soil of 
strictly definite composition, yet the conclusion which 
we draw is true for all classes of soil. 

It is an undouhted fact, that the ground must al- 
ways, and under all circumstances, contain a larger 
amount of nutritive substances than the crop grown on 
it. Supposing the soil to contain, instead of the hun- 
dred-fold, only the seventy or fifty-fold quantity of the 
nutritive elements in the crop, we infer from the law 
of the immobility of these elements, that, to double the 
crop, we must add to the field seventy or fifty times 
the quantity of mineral constituents contained in the 
produce. In practice the case is difierent, for no actual 
field, like our ideal one, contains pliosphoric acid, pot- 
ash, and silicic acid in exactly the relative proportions 
in which they exist in the ash of rye or wheat. Most 
fields which are suitable for cereals are fruitful also for 
potatoes, clover, or turnips, Avhich extract from the soil 
much more potash than the cereals. 

Therefore to convert a rye soil containing more than 
8900 kilogrammes of potash, per hectare (2|- acres), into 
a wheat soil, would not require an addition of 1300 
kilogrammes of potash, but a proportionately less 
amount would fully answer the purpose. 

We shall hereafter discuss at greater length the re- 
lations existing between the composition of a soil and 
its fertility. The main conclusion, which the above fig- 
ures are intended to illustrate, is the practical impossi- 
bility of converting a rye soil into a wheat soil by supply- 
ing the deficient ash constituents, or of making a wheat 
field by the same means produce half as much again as 
an average crop. Admitting this might be readily ac- 
complished,- experimentally, on a small area, yet the 
price of phosphoric acid, potash, or even of solnble silica, 
and the impossibility of procuring them for a large num- 
ber of fields, though in a given field only one of these 
substances had to be increased in the proportion stated, 



PRODUCTIVE POWER OF EACK SOIL VARIES. 129 

would oppose insuperable obstacles to the conversion 
or improvement of land. 

The law of the immobility of the mineral elements 
in the soil explains the agricultural experience of ages, 
that almost universally, under like climatic conditions, 
certain fields are suited for certain plants only, and 
that no plant can be profitably cultivated upon a soil, 
unless the mineral contents of the soil are in proportion 
to the special requirements of that plant. 

In practice, it is quite impossible, by a supply of 
mineral substances, to improve the land of an entire 
country, so that it shall yield crops considerably more 
abundant than the natural store of food elements in the 
soil enables it to produce. 

Every field has a real and an ideal maximum of 
productive power corresponding to the nutritive sub- 
stances which it contains. Under the most favourable 
cosmical conditions, the real maximum corresponds to 
that portion of the total amount of nutritive elements, 
which is present in the soil in an available form, i. e. 
in a state of physical combination with the soil ; the 
ideal maximum is what might possibly be obtained if 
the rest of the nutritive substances, which are in chem- 
ical combination, were converted into an available 
form, and distributed through the soil. 

Hence, the art of the agriculturist mainly consists 
in selecting such plants as will thrive best on his land, 
in adopting a proper system of rotation, and in using 
all the means at his command to make the nutritive 
elements in chemical combination available for plants. 

The achievements of practical agriculture in these 
respects are wonderful, and they demonstrate that the 
triumphs of art far exceed those of science, and that 
the farmer, by aiding the agencies which improve the 
chemical and physical condition of his land, can obtain 
much more abundant crops than by supplying nutritive 
matters. Because, what he can supply in the shape of 
manure, with due regard to a proper return, is so small 
in comparison with the store of nutritive matter con- 

6» 



130 THE SOIL. 

tained in a fruitful soil, that a perceptible increase of 
produce can hardly be expected to result from it. 

But what the farmer may achieve by manuring is 
at best the result — unquestionably a most important 
one — that his crops sufier no diminution. Where they 
actually increase, this is less attributable to the addi- 
tion made to the store of mineral constituents than to 
their distribution, and to the fact that certain quantities 
of inoperative substances have been rendered available. 

If we wished, by increasing the phosphoric acid re- 
quired for the formation of seed, to enable a wheat-field 
yielding an average produce of six grains to give two 
additional grains, it would be necessary to increase by 
^rd the whole amount of the phosphoric acid present in 
the field, and serving for the formation of seed. For it 
is always but a small fraction of the total quantity sup- 
plied that comes into contact with the roots of the 
plants ; and that they may be able to absorb this |^rd 
more, it is indispensably necessary to increase the phos- 
phoric acid by ^rd in all portions of the soil. This re- 
flection explains the rule found true in experience, that 
to produce a marked efl'ect upon crops by manuring, a 
mass of manure must be laid on, utterly disproj)ortion- 
ate to the expected increase. 

A manure will exercise its beneficial action upon a 
field in the most marked manner, when it establishes a 
more suitable i*elative proportion between the several 
mineral constituents in the soil ; because upon this pro- 
portion the crops are dependent. No special argument 
is needed to demonstrate, that where a wheat soil con- 
tains just so much phosphoric acid and potash as will 
suffice to afiTord the quantity of these two substances 
required for a full wheat crop, and no more (accord- 
ingly for every part by weight of phosphoric acid two 
parts by weight of potash), an additional supply of one- 
half more, or even of double the quantity of potash, 
cannot exercise the slightest possible influence upon 
the crop of corn. The wheat-plant requires for its full 
developement a certain relative proportion of both nu- 
tritive substances, and any increase of one beyond this 



BELATIONS EXISTING AMONG FOOD ELEMENTS. 



131 



proportion makes the other not a whit more effective, 
because the additional supi)ly exercises by itself no 
action. 

An increase of phosphoric acid alone has just as 
little influence in making the returns greater, as an in- 
crease of potash alone : this law applies equally to 
every nutritive substance, potash, magnesia, and silicic 
acid ; no su])ply of these substances beyond the re- 
quirement of the wheat-plant, or its capacity of absorp- 
tion, will have any effect upon its growth. The relative 
proportions of the mineral substances, which the plants 
draw from the soil, are easily determined by analysing 
the ashes of the produce. It is found by analysis that 
wheat, potatoes, oats, and clover receive the following 
proportions of phosphoric acid, potash, lime, magnesia, 
and silicic acid : — 





Phosphoric 
acid. 


Potash. 


Lime and 
magnesia. 


Silicic acid. 


Potatoes (tubers) .... 

0- \ZZ\-- 

Clover 

Average 





2-0 
3-2 
21 
2-6 

2-5 


0-48 
1-03 
4-0 

1-5 


5-T 
0-4 
5-0 
1-0 

3 



Supposing wheat, potatoes, oats, and clover to be 
cultivated in a field for four years in succession, each 
of these plants will absorb from the soil the proportion 
of mineral constituents which it requires ; and the sum 
total divided by the number of years, viz. four, shows 
the average relative proportion of all the nutritive sub- 
stances which the soil has lost. 

If, in the formula, 



Phosphoric acid. 
n(10 



Potass. 



Lime and magnesia. Silicic acid. 

: 1-5 : 3-0) 

we determine the value of n, which is meant here to 
designate the number of kilogrammes of phosphoric 



132 THE SOIL. 

acid wliicli the four crops have received from the soil, 
we iiud for the wheat crop 26 kilogrammes of phos- 
phoric acid, for the potato crop 25 kilogrammes, for 
tlie oat crop 27 kilogrammes, and for the clover crop 
36 kilogrammes — altogether, 114 kilogrammes ; multi- 
plying the above proportional numbers by this num- 
ber, we obtain the sum total of all the nutritive sub- 
stances extracted from the soil by the four crops. 

With the help of these proportional numbers, we 
are better able than before to give some more accurate 
explanations. 

Suppose that the soil of a certain field contains, in 
an available state, the requisite quantities of phosphoric 
acid, potash, lime, and magnesia, to supply the four 
crops stated above, but that it is deficient in the proper 
proportion of silicic acid — containing, for example, for 
1 part by weight of phosphoric acid, only 2^ parts of 
silicic acid, in an available condition — this deficiency 
will, in the first place, be felt in the crops of cereal 
plants, whilst the potato and clover crops, on the con- 
trary, will not be at all diminished. It will depend 
upon the weather to determine whether this deficiency 
in the crop of cereal plants extends both to corn and 
straw or is confined to the straw alone. A want of 
potash, in proportion to all the other constituents, will 
barely affect the wheat and oat crops, but it will reduce 
the potato crop ; in like manner, a want of lime and 
magnesia will impair the clover crop. 

If the ground can furnish one-tenth more potash, 
lime, magnesia, and silicic acid than corresponds to the 
given proportion of phosphoric acid — thus, if, 

Phosphoric t>„«„„i. Lime and cv • 'j 
acid. ^°^'''^- Magnesia. S'l»cic acid. 

Instead of 1 2-5 1-5 3-0 

Tlie ground should be able 

to furnish 1 2-75 1-65 3-3 

the crops would not turn out larger than before. But 
if, in such a field, the quantity of phosphoric acid is 
increased, the produce will increase, until the right 
proportion is restored between the phosphoric acid and 



EFFECT OF INCREASING ONE MINEKAL CONSTITUENT. 133 

the other mineral constituents. The additional supply 
of phosphoric acid serves in this case to increase the 
amount of potash, lime, and silicic acid in the produce ; 
but if this additional supply exceeds one-tenth of the 
phosphoric acid present in the soil, the quantity in ex- 
cess remains inetiective. Up to this limit, every pound 
— nay, every ounce — of phosphoric acid supplied has, 
in this case, a fully determinate action. 

If potash or lime alone is wanted to restore the 
right proportion among the nutritive substances in the 
soil, a supply of ash or lime will increase the produce 
of all the crops — the additional supply of lime etfecting, 
in this case, an increase in the amount of phosphoric 
acid and potash in the augmented produce. 

If we find that a soil will not bear a remunerative 
crop of cereal plants, though it remains fruitful for 
other plants, such as potatoes, clover, or turnips, which 
require just as much phosphoric acid, potash, and lime, 
as the cereals, we may assume that the soil had the 
latter substances in excess, but was deficient in silicic 
acid. And if, in the course of two or three years, dur- 
ing which other produce is cultivated on it, the land 
recovers its fertility for cereals, this must be because it 
contained, though unequally divided and distributed, 
an excess of silicic acid also, which, during the fallow 
season, migrated from the places where it was in excess 
to those where it was deficient ; so that when the sub- 
sequent period of cultivation began, there was in all 
these places the right proportion of all the nutritive 
substances needed by cereal plants. 

For similar reasons, if peas or beans can be culti- 
vated on a given field only at certain intervals, and ex- 
perience shows that skilful, industrious tillage is usually 
more effective than manure in shortening these inter- 
vals, we may infer that in such cases the nutritive sub- 
stances were not deficient in total quantity in the whole 
field, but in proper proportion in all parts of the field. 



CHAPTEK III. 

ACTION OF SOIL ON FOOD OF PLANTS IN MANUEE. 

Manures : meaning of the term •, their action as food of plants and means for im- 
proving the Boil — Elfect on soils with dilfereiit powers of absorption — Enchsoil 
possesses a detinita power of absorption ; the distribution of the food of plants 
in the soil is inversely to the power of absorption ; means of counteracting the 
absorptive power — Absorption rumber, notion of; comparison of in difl'erent 
fields , its importance in husbandry — Soil saturated with food of plants ; its 
comportment with water— Quantity of food to saturate a soil— A saturated 
soil not required for the growth of plants— Manuring may be compared to the 
application of earth saturated with food — Importance of the uniform distribu- 
tion of food in manures ; fresh and rotted stall manure ; compost ; importance 
of powdered turf for the preparation of manure— Quantity of food in un- 
manured fields and their powers of production ; increase of the latter appa- 
rently out of proportion to the manure added ; experiments on this point ; 
explanation ; composition of the soil and its absorptive power compared with 
the requirements of the plants to be cultivated on it; surface and subsoil 
plants, tlie tillage and manuring respectively required by each — Clover sick- 
ness ; experiments of Gilbert and Lawes ; their conclusions ; yalue of them. 

THE term 'manure' is commonly used to designate 
all matters which, applied to a field, will increase 
the amount of its future produce, or, when the land has 
been exhausted by cultivation, will restore its capability 
of yielding remunerative harvests. 

Manuring agents act partly in a direct manner as 
elements of food, and partly, like common salt, nitrate 
of soda, or salts of ammonia, by enhancing the efi'ect of 
the mechanical operations of tillage, so that they fre- 
quently exert as favourable an influence as the actual 
increase of the nutritive substances in the ground. 

Of the two last-named compounds, nitrate of soda 
contains a nutritive substance in the nitric acid, and 
salts of ammonia in the ammonia. Hence it is ex- 
tremely difficult in individual cases to determine 
whether their action is due to their nutritive constitu- 
ents, or to the fact that they have brought about the 
absorption of other nutritive substances. 



ARABLE SOILS ABSOKB MINEKAL MATTERS. 135 

In a fertile soil tillage and manuring have a definite 
relation to one another. If, after a rich harvest, the 
field is prepared by tillage alone to produce a similar 
rich crop in the next year, that is, if the mechanical 
means are sufficient to distribute the store of nutritive 
substances so uniformly that the plants of the following 
season will find as much nutriment in all parts of the 
soil as during the last, any further supply of mineral 
constituents by manuring would be mere waste ; but, 
where a field is not in that condition, the deficiency 
must be supplied by manure, in order to restore the 
original power of production. Thus, in a certain sense, 
the mechanical operations of tillage and of manure are 
supplementary to one another. 

Of two similar fields, manured in exactly the same 
way, if the one has been well tilled, and the other bad- 
ly tilled, the former will yield a richer crop, i. e. the 
manure seems to have a better effect upon this than 
upon the badly tilled field. 

If one of two farmers knows his land better, and 
cultivates it more judiciously than the other, the former 
will, in a given time, obtain as good crops with less 
manure, or richer crops with the same quantity of 
manure. 

All these facts should be considered in estimating 
the value of manuring agents ; but, as science has no 
standard for measuring the results of the mechanical 
operations of tillage, this cannot be taken into account 
here, and we must confine ourselves to that which can 
be scientifically measured and compared. 

When two fields are equally rich in nutritive sub- 
stances, it often happens that the one, by tillage alone, 
or by tillage combined with manuring, will be brought 
much sooner than the other into a condition to yield a 
succession of remunerative crops of cereal or other 
plants. 

On a light sandy soil, all kinds of manure act more 
rapidly and effectively than on clay. The sand is more 
grateful, say the farmers, for the manure bestowed 
upon it, and yields a more abundant return than other 



136 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

soils for what it has received. The nitrogenous 
manures, such as wool, horn-shavings, bristles, and 
blood, which, as we know for a certainty, act by the 
formation of ammonia, frequently exercise a far more 
favorable influence upon many plants than ammonia 
itself. In other cases, bone-earth acts more powerfully 
upon the future crop than superphosphate of lime ; and 
sometimes ash will prove more fertilising than if the 
amount of potash contained in it were directly laid 
ujDon the field. 

All these facts are most intimately connected with 
the faculty of arable soils to extract or absorb phos- 
phoric acid, ammonia, potash, and silicic acid from 
their solutions. The restoration of the productive 
power to an exliausted field by the mechanical opera- 
tions of tillage and fallowing alone, without manure, 
presupposes that in certain parts of the field there must 
have been an excess of nutritive substances which dis- 
persed in the soil and extended to other places where 
such substances were deficient. 

This distribution demands a certain time. The 
excess of nutritive elements must first be dissolved, that 
they may be able to move towards those parts which 
have lost their elements of food by a previous harvest. 
The closer these superabundant deposits lie to each 
other, the shorter is the way over which the substances 
have to travel ; and the less the absorptive power of 
the intervening earth particles for these nutritive sub- 
stances, the more speedily will the productive power 
of the soil be restored. 

Every arable soil possesses, for potash and the other 
substances mentioned, a determinate power of absorp- 
tion, which may be expressed by the number of milli- 
grammes absorbed by 1* cubic decimetre ( = 1000 cubic 
centimetres) of earth. Tlius, for instance : — 

Cubic Cubic 
decimet. inches. Milligrammes. Grains. 

1 = 61 of lime soil from Cuba absorbed 1360 = 21 potash. 

1 " loam " Bogenhausen " 2260 = 35 " 

1 " soil " Weihenstephan " 2601 = 40 " 

1 " soil " Hungary " 3377 = 52 " 

1 " garden mould " Munich " 2344 = 36 " 



ABSORPTIVE rOAVER OF SOIL FOR SILICIC ACID. 137 

It "vvill be seen at once that these differences in 
absorjitive power are very considerable. One vohime 
of earth i'roni AVeihenste])han absorbs nearly twice as 
mncli potash as an equal bulk of soil from Cuba ; the 
Hungarian earth, here examined, absorbs 2^ times as 
much. 

These figures show that a certain quantity of pot- 
ash, say 26U0 milligrammes, if supplied to the Weihen- 
stephan soil, will spread in a space of 1 cubic decimetre 
of earth. If we were to pour the potash, in solution, 
on a small plot of ground, 1 square decimetre in area, 
the potash would penetrate to a depth of 1 decimetre 
(= 8-94 inches), and no deeper ; every cubic centimetre 
[= -061 cubic inch) would receive 2*6 milligrammes 
(= '04 grain) of potash, but the layers beneath would 
receive none, or at least no appreciable quantity of it. 

If the same solution were poured on an equal area 
of Hungarian or Cuban soil, the potash filtering 
through w^ould penetrate, in the former, to a depth of 
someM-hat above 7 centimetres {= 2-7 inches) ; in the 
latter, to a depth of 19 centimetres (= 7*5 inches). 

The diftusii)ility of potash in a soil is in an inverse 
ratio to the absorptive power of that soil ; half the 
absorptive power corresponds to double the diff'usibility. 
In a similar way potash will spread in a field during 
the time of fallow. From the spot where the potash is 
set free from a silicate by disintegration, it Avill difi'use 
itself through a volume of earth so much the larger in 
proportion as the absorptive power of the earth for 
potash is smaller. 

The absorptive power of arable soil for silicic acid 
diff'ers just as much as for potash. 

Thus from a solution of silicate of potash, 1 cubic 
decimetre (= 61 cubic inches) of these difterent soils 
absorbed the following quantities of silicic acid : — 

Forest soil. Iliingnrian. Garden mould I. BotrcnUauscn. Garden mouKl II. 
Milligr. Grains. Milligr. Grains. Milligr. Grains. Millis^r. Grains. Milligr. Grains. 
15=0-23 2644=43-8 2425 = 37-3 2007 = 31 1085=16-7 

Whence to express the relative diff'usibility of silicic 



138 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

acid in these soils, we have the following propor- 
tion : — 

Hungarian. Garden mould I. Bogenhauscn. Garden mould II. Forest soil. 
1-0 1-09 1-31 2-43 17-6 

The same quantity of silicic acid which would satu- 
rate 1000 cubic centimetres of Hungarian earth, would 
furnish a maximum supply for 1311 cubic centimetres 
of Bogenhausen loam, 2430 cubic centimetres of gar- 
den mould II., and 17,600 cubic centimetres of forest 
soil. 

Ammonia, in the pure state, or in the form of salts 
of ammonia, is absorbed by arable soil just in the same 
way as potash : one kilogramme (= 2'2 lbs.) of the fol- 
lowing earths will absorb respectively these quantities 
of ammonia : — 



Cuban. 


SohleisBheim. 


Garden mould. 


Bogenhausen. 


illigr. Grains. 


Milligr. Grains. 


Milligr. Grains. 


Milligr. Grains. 


5520=85 


8900=60 


3240=49-9 


2600=40 



which gives the following numbers for the relative 
diffusibility of ammonia : — 

Cuban. Schleissheim. Garden mould. Bogenhauscn. 

1-0 1-24 1-50 2.12 

The absorptive power of arable soils for phosphate 
of lime, j^hosphate of magnesia, and phosphate of mag- 
nesia and ammonia, may be determined in the same 
way, and the relative diffusibility of these several con- 
stituents in different soils may be expressed numerically. 

By the term ' absorption number,' we designate, in 
the following pages, tne quantity reckoned in milli- 
grammes (= 0-0154 grain) of the several mineral con- 
stituents, which one cubic decimetre (= 61 cubic in- 
ches) of earth extracts from their solutions. 

To determine the condition of a field, the action of 
the manures applied to it, and the depth to which the 
several nutritive substances will penetrate, it is import- 
ant to establish proportionately the absorptive power 
of the soil for each of them ; thus, for example, 1 cubic 
decimetre of Bogenhausen loam absorbs : — 



riSPEKSION OF PHOSPHATK OF LIME IN SOIL. 



139 



Relative diffusibility 



Milligrammes. 
2600 
1-0 



riiospliatoof 

Majjiiesia and 

Auuuonia. 



Millioirammes 
25-C5 
1-01 



Milligrammea. 
2aGt) 
1-10 



riu)8)ihate 

of 

Lime. 



Milligrammes. 
1098 
2-36 



Accordingly, the second scries of these numbers 
expresses that if a certain quantity of ammonia in its 
passage through the soil penetrates to a depth of 10 
centimetres, the same quantity of jjotash will attain a 
depth of 11 centimetres, and a like quantity of phosphate 
of lime will reach 23*6 centimetres. 

In a soil like the Bogenhausen, which absorbs per 
cubic decimetre 1098 milligrammes of dissolved phos- 
phate of lime, let us suppose that granules of phosphate 
of lime are dispersed, and that in one spot of the 
ground one of these granules weighing 22 milligrammes 
(^ of a grain) during the course of a certain time be- 
comes soluble in carbonic acid water, and spreads in 
the surrounding soil ; first of all the earth immediately 
around this granule will be saturated with phosphate 
of lime, then as the carbonic acid remains in the water 
and its solvent power continues, a fresh solution will 
be formed, which will again offer phosphate of lime for 
absorption to a wider extent of earth ; at length, when 
the 22 milligrammes of phosphate of lime are thorough- 
ly diffused in the surrounding earth, they will supply 
20 cubic decimetres of earth with the maximum of this 
nutritive substance in the form best suited for absorp- 
tion. The rapidity with which the phosphate of lime 
will dissolve and spread depends upon its extent of sur- 
face ; accordingly, if we suppose the granule to be 
converted into a line powder, a solution will be formed 
richer in phosphate of lime just in proportion to the 
greater number of particles exposed within the same 
time to the solvent action of the carbonic acid. There- 
fore, assuming that in a certain state of greater division 
twice or three times as much is dissolved in a ffiven 



140 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

time, we infer that distribution under favourable cir- 
cumstances will take place in one-half or one-thii'd of 
the time it would take without the division. 

If, therefore, in a given case the restoration of the 
productive power in a soil by fallowing or manuring 
depends upon the earth when drained of phosphoric 
acid by the roots of plants receiving the needful phos- 
phoric acid back again from the surrounding earthy 
particles, it follows that with an equal amount of earthy 
phosphates the time required to accomplish this end 
will be shortened in proportion to the division of the 
earthy phosphates. 

Straw manure, after decay, leaves silicate of potash 
behind, and in the process of putrefaction evolves car- 
bonic acid, which by its action upon the silicates sets 
free silicic acid ; hence by using this manure the diffu- 
sion of silicic acid must be promoted as the organic 
matters absorb none of it, and they, when mixed with 
the earth, must diminish the absorptive powers of the 
soil. 

The forest soil above mentioned absorbed only very 
small quantities of silicic acid from its alkaline solu- 
tions ; and it is evident that the addition of such soil to 
the Hungarian earth would have the effect of diffusing 
through a larger volume of earth the silicic acid set free 
by disintegration. 

It is not, however, the case with every soil, that its 
absorptive power for silicic acid decreases in equal pro- 
portion to the quantity of combustible substances 
which it contains. Thus the Hungarian earth above 
alluded to contains more (9*8 per cent.) combustible 
matter than the Bogenhausen loam (8*7 per cent.), yet 
its absorptive power for silicic acid is not less but 
greater than that of the latter. Hence it follows that 
there are other circumstances which influence the 
absorptive power of the soil, and consequently the 
diffusibility of silicic acid. A soil abounding in hy- 
drated silicic acid will, under any circumstances, absorb 
less silicic acid than one deficient in that acid, even 



FOOD OF PLANTS IN SANDY SOILS AND LOAMS. 141 

though the latter soil should contain a much larger 
amoiuit of organic substances. 

The 'absorption numbers' of two different arable 
soils alford no criterion for determining the quality of 
the soil or the amount of nutritive substances which it 
contaius ; they merely tell us that, in the one soil, the 
elements of the food of plants will spread beyond cer- 
tain places, further than in the other ; that the one soil 
opposes greater obstacles to their ditfusion than the 
other. The farmer, in learning the strength of these 
obstacles, finds out by experience whether they exert a 
beneficial or adverse influence upon the cultivation of 
his fields, and ascertains the means of removing the 
injurious or strengthening the beneficial influences. 

On comparing a fruitful sandy soil with an ecpially 
fruitfnl loam or marl, as regards the nutritive sub- 
stances contained in them, we are surprised to find that 
the sand- with one-half or even one-fourth, of the total 
substances contained in the loam, will furnish an 
equally rich harvest. To understand this circumstance 
properly, we must remember that the nutrition of a 
plant depends less upon the quantity, than upon the 
form of the nutriment in the soil ; just in the same 
way as, for example, half an ounce of animal charcoal 
presents as large an acting surface as a pound of wood 
charcoal. If the smaller quantity of nutritive sub- 
stances in the sandy soil presents as large a surface for 
absorption as the larger quantity of those substances in 
the loam, the plants must thrive as well upon the 
former as upon the latter. 

If a cubic decimetre of a fruitful loam is mixed 
with 9 cubic decimetres of silicious sand, so that every 
particle of sand is surrounded with particles of loam, 
as many root-fibres and particles of loam will come 
into contact in the mixed as in an equal volume of the 
unmixed soil ; and if all the particles of loam can yield 
the same nutriment, plants will receive from the mixed 
just as much as from the unmixed soil, though, on the 
whole, the latter is ten times richer. 

All fruitful sandy soils consist of a mixture of sand 



142 ACTION OF son, ON FOOD OF PLANTS IN MANUKE. 

with more or less clay or loam ; and as silicious sand 
has a very limited power of absorbing potash and the 
other mineral constituents of plants, the ingredients of 
the supplied manure, which liave become soluble, 
S]3read sooner and penetrate deeper into a sandy soil, 
which also gives back comparatively more of them than 
any other soil. In many cases, therefore, a stiiF loam 
may be improved by sand ; as, on the other liand, the 
addition of loam to a sandy soil will cause the nutritive 
substances, supplied by the manure, to remain nearer 
the surface or to be retained more firmly in the arable 
top layer. 

But as a sandy soil gives up at harvest more nutri- 
tive substances in proportion to w^hat it contains, than 
a fruitful loam, a more speedy exhaustion is the conse- 
quence ; its power of production does not last long, 
and can only be sustained by, frequent manuring, to 
supply the constituents which have been removed. 
Exactly in the same degree, as the manure acts more 
beneficially in restoring the productive power, the 
effect of the mechanical operations of tillage becomes 
less marked. 

The same causes which restore to an exhausted loam 
a large portion of its lost productive power, if the land 
is but sufiiciently broken up by the plough, are at work 
in a sandy soil also ; but they produce little or no re- 
sult, because the sand is deficient in those substances 
which the action of the plough is intended to render 
available. 

As the surface of a hectare (2-| acres) represents 1 
million square decimetres, the absorption numbers ex- 
press the number of kilogrammes of potash, phosphoric 
acid, and silicic acid, wdiich, when applied on a field, 
will spread from the surface downwards to a depth of 
10 centimetres (about 4 inches). Yolker, Henneberg, 
and Stohmann, in experiments made upon diff'erent 
soils to determine their absorption numbers for am- 
monia, observed that the earth retained a greater 
quantity from a concentrated than from a dilute solu- 
tion of ammonia or salts of ammonia ; whence it fol- 



ABSORPTION OF AMMONIA BY SOIL. 143 

lows, as a matter of course, that the ammonia is divided 
between the water and the soil, and that from a soil 
fully saturated with ammonia, pure water will extract 
a certain quantity of it ; just as charcoal will complete- 
ly withdraw the colouring matter from a slightly 
coloured fluid, but from one more deeply coloured will 
extract a much larger quantity ; a part of which, how- 
ever, is but feebly combined and may be removed by 
water. 

In Volker's experiments, treatment with a copious 
amount of water extracted one-half the ammonia from 
a soil saturated therewith ; the other half was retained 
by the earth. 

Soils which contain much decaying vegetable mat- 
ter absorb more ammonia and retain it more firmly 
than soils that are poorer in decaying organic substan- 
ces. Even assuming that two cubic decimetres of 
earth, instead of one, are required to retain completely 
the amount of ammonia indicated by the absorption 
number, it is clear that ordinary manuring with an 
agent abounding in ammonia, such as guano or salts of 
ammonia, can enrich the earth with this substance only 
to a very inconsiderable depth. 

To saturate with ammonia, a hectare (2|- acres) of 
Bogenhausen loam, ft'om the surface downwards to the 
depth of one decimetre, fully, or to half-saturate it to 
the depth of two decimetres (7'8 inches), would require 
a supply of 2G00 kilogrammes or 52 cwts. of pure am- 
monia, or 200 cwts. of sulphate of ammonia. 

If 800 kilogrammes of guano, containing 10 per 
cent, of ammonia, are applied to a hectare of Bogen- 
hausen soil, the amount of ammonia added is 80 kilo- 
grammes (= 176 lbs.), which is a little more than the 
thirtieth part of the quantity required to half-satm*ate 
the soil to a depth of 20 centimetres. Without the 
plough and harrow, the quantity of ammonia contained 
in the guano would not penetrate, at the furthest, 
deeper than 7 millimetres (= 0-27 inch). But to thrive 
well, plants do not require a soil saturated with nutri- 
tive substances ; for, the absorption numbers we have 



14:4: ACTION OF SOIL ON FOOD OF PLANTS IN MANUEE. 

quoted sufficiently show liow far tlie arable soils are 
from a state of complete saturation. All that plants 
need for their proper nutrition is that their roots, down- 
wards in the soil, should come in contact with a certain 
quantity of saturated earth ; and the mechanical opera- 
tions of tillage have the important object of conveying 
earthy particles saturated with nutritive substance, and 
of mixing them with others, which by preceding culti- 
vation have become poorer in those constituents. 

The average crop from a hectare of wheat (2000 kilo- 
grammes — 4400 lbs. of grain, and 5000 kilogrammes 
= 11,000 lbs. of straw) contains 52 million milli- 
grammes = 114-4 lbs.) of potash, 26 million milli- 
grammes (= 57*2 lbs.) of phosphoric acid, and 54 mil- 
lion milligrammes (= 118-8 lbs.) of nitrogen. As- 
suming the nitrogen to be supplied by the soil, the 
wheat plants growing on a square metre (= 10'75 
square feet) receive the ten-thousandth part of the pot- 
ash, phosphoric acid, and nitrogen, or altogether 13,200 
milligrammes (= 203-3 grains). Supposing 100 plants 
to grow upon a square metre, each of these takes up 
from the soil 1'.2 milligrammes of these constituents, or 
54 milli«;rannnes of nitroo-en = 65 millio-rammes or 1 
grain of ammonia, 52 milligrammes (= 0-8 grain) of 
potash, and 26 milligrammes (= 0-4 grain) of phos- 
phoric acid. 

Each cubic centimetre (= '06 cubic inch) of Bogen- 
hausen loam absorbs to saturation 2*6 milligrammes 
(=•04 grain) of ammonia, 2-3 milligrammes {== 0"35 
grain) of potash, and 0-5 milligrammes (= '008 grain) 
of phosphoric acid ; therefore, to restore a sufficiency 
of these constituents which the wheat plant has taken 
from the soil, would require a supply of 25 cubic cen- 
timetres of the saturated earth, and 25 milligrammes 
of phosphate of lime for each square decimetre of the 
field. Calculated upon a square decimetre ( = 15|- 
square inches) of surface and a depth of 20 centimetres 
( =7-8 inches), these 25 cubic centimetres constitute the 
eightieth part of the entire mass of earth. 

The experiments of Nageli and Zoeller, before de- 



EAKTU SATURATED WITH MINEKAL MATfEK. 1-15 

scribed, furnish a good example of this kind of manur- 
ing. Tlic manure consisted of turf, partly saturated 
-with nutritive substances and mixed with three volumes 
of turf ahnost absolutely unfruitful ; this constituted a 
soil of the same degree of fertility as good garden 
mould. 

iSuch an addition of earth saturated with mineral 
constituents does not usually take i)lace ; but the ordi- 
nary method of manuring comes exactly to the same 
result. The field is dressed with licpiid or solid manur- 
ing matters containing nutritive substances, which com- 
bine immediately if in solution, gradually if requiring a 
certain time for solution, with the earthy particles with 
which they are in contact, and saturate them ; and it is 
properly this earth, saturated icith manuring matters 
on its outermost surface or in the inner j^artsvydh tohich 
the fanner manures, i. e. Avith which ho replaces the 
mineral constituents withdrawn from the soil. 

Experience has taught the agriculturist which parts 
of the soil nuiy be enriched with nutritive substances 
most profitably for himself, or rather for his plants ; 
and it is remarkable in the liighest degree how he has 
found out the proper method of numuring in accordance 
with the nature of the intended crop, the soil, and the 
period in which the plants are developed ; also whether 
to proceed by simple top-dressing or by ploughing the 
manure in to a greater or less depth.* 

In these respects the successes of the agriculturist 
would be still greater if the nutritive substances con- 
tained in the manure principally used, namely, farm- 
yard manure, were more uniformly mixed arid distrib- 
uted, because this would lead to a more uniform distri- 
bution of them in the soil. 

Farm-yard manure is a very irregular mixture of 
decaying straw and vegetable remains, combined with 
solid animal excrements, the latter constituting the 
smaller portion of the whole mass : it is soaked with 
fluids which hold annnonia and potash in solution. If 
a hundred samples be taken from a hundred difierent 

* ' Journ. of the Roval Agric. Soc. England,' t. 21, p. 330. 

7 



146 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

parts of a dung-heap, the analysis of each sample will 
show clifi'erent proportions of nutritive constituents : 
hence it is evident that by a dressing with farm-yard 
manure hardly two spots in the soil will receive the 
same amount of nutritive substances. 

The spot occupied by a dung-heap on a field during 
rainy weather, will be marked in the whole period of 
vegetation, and often even in the second year by a more 
luxuriant growth of plants, especially of cereals, though 
the plants growing on it will not always furnish a per- 
ceptibly greater yield of grain. If the potash and am- 
monia received by this spot above what was required 
for the formation of grain, had been more evenly 
distributed, and thus accessible to the plants in other 
places, the yield of corn from those plants would have 
been increased ; whereas the excessive accumulation in 
one place merely increased the yield of straw. The 
unequal distribution of the other ingredients of farm- 
yard manure in the soil leads to a similar inequality in 
the developement of the several parts of the cereal 
plants. On an ideal field, with the nutritive substances 
supposed to be distributed with perfect uniformity, and 
all accessible to the roots, all the cereal plants, other 
conditions being the same, should attain the same 
height, and each ear yield the same number and weight 
of grains. 

In the short, rotten farm-yard manure, the nutritive 
substances are much more uniformly distributed than 
in the fresh straw manure ; and the agriculturist effects 
a still more uniform diff'usion by mixing the dung with 
earth, and turning it into so-called compost. As dung 
and all other manuring agents act only through the 
onediuni erf the earthy jpai'tides that have hecome sat- 
urated with the nutritive siihstances contained in the 
manure^ it is, under certain circumstances, advanta- 
geous for the farmer to prepare a saturated earth, by 
help of his farm-yard manure, and to use this composi- 
tion, which may of course be made on the field itself. 
If, in accordance with Voelker's valuable experiments, 
we assume one cubic metre ( = 35 cubic feet) of farm- 



USE OF EAll'rn SATURATED WITH MANURE. 147 

yard manure (500 kilogrammes or KJOO pounds) to con- 
tain 6G0 pounds of water, 6 pounds of potash, and 12 
pounds of ammonia ; and if this were mixed with 1 
cubic metre of earth, of which 1 cubic decimetre { = 61 
cubic inches) absorbs 3000 milligrammes ( = 40-2 grs.) 
of potash, and GOOO milligrammes ( = 92-4 grs.) of am- 
monia ; then, after the complete decay of organic matter 
in the manure (about 25 per cent, of its weight), and 
the evaporation of one-half of the water, the result 
would be 1^ cubic metre of earth fully saturated with 
all the nutritive substances in the manure. Soils that 
will absorb the stated amount of potash and ammonia 
are everywhere to be found, and the farmer will have 
no difficulty in choosing the earth most suitable for his 
compost heaps. 

It is well known that dung exercises a mechanical 
action also, tending to diminish the cohesion of a com- 
pact soil, or to make a heavy soil lighter and more 
porous. For soils of this kind composts are not so well 
suited ; and, instead of the earth, some very loose body 
ought to be substituted for mixing with tlip manure. 
Turf-dust will be found to answer the purpose best.* 

If the crops obtained from many fields by manuring 
with farm-yard manure, bone-earth, guano, and in many 
cases also with wood-ashes and lime, are compared with 
what the same fields will yield in the unmanured state, 
the effect of these manures seems truly marvellous. 

The yield of an unmanured field must correspond 

. * It is, perhaps, much more important than manuring with composts, 
whicli always involves much labour and more carriage, to take advantage 
of the absorbent properties of earth and turf, for fixing the nutritive sub- 
stances contained in liquid manure. By covering the ground of a dung- 
hill, on an area of 10 metres square (:=10'5 sq. feet) with a layer of loose 
turf, 1 metre (== 3'3 feet) deep, a bed of 100 cubic metres (= 3,500 cubic 
feet) of turf is formed, into which the li(juid portion of the manure in the 
dunghill may safely be allowed to soak without the least risk of losing the 
smallest portion of its useful ingredients. The turf may then be used, like 
dung, for manuring, and of course must be renewed every yenr. On fields 
which are not tilled, such as meadows, li([uid manure will naturally act 
with greater rapidity. The turf found in tlie neighbourhood of Munich, 
when reduced to powder, absorbs 7'892 grammes (=122 grains) of potash, 
and 4-1C9 grammes (= G4 grains) of oxide of ammonium, per 1000 cubic 
centimetres {= 61 cubic inches) weighing 330 grammes (lli ozs.). 



148 ACTION OF SOIL ON FOOD OF PLANTS IN MANUEE. 



"with the available nntritive substances which it contains ; 
a lower crop corresponds to a smaller store of these mat- 
ters. In any one of the cases stated, if we compare the 
amount of nutritive substances in the unmanured por- 
tion of a field with the crop which it produces, and then 
compare the additional nutritive substances or the 
quantity of dung with the increased crop, the increase 
appears to be beyond all proportion much greater than 
the additional supply. Hence we are led to suppose 
that the phosphoric acid, potash, and ammonia given 
in the manure must be much more efficacious than the 
substances present in the soil, or that the greater por- 
tion of them in the soil was ineffective, and that its 
power of production had depended chiefly upon the 
supply of manure. Thus it arises, that while some 
farmers believe that all manure can be dispensed with 
because tillage is enough to render a field productive, 
others suppose that the field can be kept fruitful only 
by manuring. All these views are based upon indi- 
vidual cases and have no general application ; for 
neither one nor the other of the contending parties 
have any clear knowledge of the true causes upon 
which the power of production of this kind is founded. 
In the experiments made in the year 1857, by order 
of the General Committee of the Bavarian Agricultural 
Union, on the action of phosphorite upon certain fields 
at Schleissheim deficient in phosphoric acid, the follow- 
ing crops of summer wheat were reaped from two plots 
of ground, one unmanured the other dressed, per hec- 
tare ( = 2|- acres), with 241-4 kilogrammes ( = 530 
lbs.) of phosphoric acid, 657'4 kilogrammes ( = 13 cwt.) 
of phosphorite decomposed by sulphuric acid : — 





1S57. 




Total crop. 


Corn. 


Straw. 


Manured with 65Y 
kilogrms. of phos- 
phate of lime .... 

Unmanured 


Kilogr. Cwt. 

5n4-'7 = 10o-0 
2301-0= 45-0 


Kilogr. Cwt. 

1301-'7=25-5 
644-3= 12-5 


Kilogr. Cwt. 

381.n-0=750 
]C.5C-7 = 32-5 



RATIO OF CKOP TO PHOSPHOKIC ACID IN SOIL. 149 

From a chemical analysis made by Dr. Zoeller, of 
the JVlunicli Laboratory, the soil of this field was found 
to give up to cold hydrochloric acid a quantity of phos- 
phoric acid, which, calculated per hectare to a de}>th of 
'25 centimetres, amounted to 237G kilogranmies = 5170 
kilogrammes of phosphate of lime. 

The quantity of phosphoric acid in the corn and 
itraw of the crop reaped amounted together to : — 

kilogr. lbs. 

From the manured plot 17'5=:38'5 of phosphoric acid. 

From the unmanurcd plot S'O^l'Z'B " 

Surplus obtained by manuring 9'5 = 20'9 " 

In the C57'-± kilogrammes of phosphorite the field 
received altogether 211 "4 kilogrammes of phosphoric 
acid ; accordingly, the surplus amounted only to j'^th 
of the phosphoric acid supplied in the manure. 

Tliere is nothing surprising in this result, as the ad- 
ditional phosphoric acid was not given to the plants but 
to the whole field. Had it been possible to surround 
each root with so much phosphoric acid or phosphate 
of lime as the surplus crop of corn and straw required 
for its formation, 9^ kilogrammes of phosphoric acid 
would have sufiiced to double the produce of the un- 
manurcd plot ; but in the way in which the manure 
was actually applied, every part of the field received an 
equal share of phosphoric acid. 

Thus, of the total amount of 241*4 kilogrammes, 
only 0*5 kilogrammes came into contact with the roots 
of the plants, the remainder, though quite suitable for 
food, remaining inactive. To enable the plant to take 
up one part of phosporic acid, it was necessary to sup- 
ply the field with five-and-twenty times this quantity. 

On the other hand, the efiect of the manure appears 
out of all proportion greater as compared with the store 
of phosphoric acid in the field. 

The quantity of phosphoric acid contained in the 
corn and straw reaped from the unmanured plot is jjiitli 
of the total amount of phosphoric acid in the field ; that 
in the surplus crop is a's^h of the phosphoric acid sup- 



150 ACTION OF SOIL ON FOOD OF PLANTS IN MANUKE. 

plied by the manure. As the manured plot gave dou- 
ble the produce of the unmanured, the effect of the 
phosphoric acid supplied by the manure is apparently 
twelve times greater than that of the acid originally 
contained in the soil. 

The quantity of phosphoric acid supplied (241*4 kilo- 
grammes) amounted to ^'^th of the total quantity in the 
field (2376 kilogrammes). If the action of both had been 
alike, the surplus crop should have corresponded to the 
additional supply, but instead of being y'^tli greater, it 
was double the crop obtained from the unmanured plot. 

This fact is explained by the absorptive number of 
the Schleissheim soil for phosphoric acid or phosphate 
of lime. 

If the store of phosphoric acid in the field had been 
uniformly distributed in the form of phosphate of lime 
(5170 kilogrammes) to a depth of 25 centimetres (9*8 
inches), each cubic decimetre (61 cubic inches) w^ould 
contain 2070 milligrammes (32 grains), each cubic centi- 
metre about 2 milligrammes of phosphate of lime. 

The field was manured with 657"4 kilogrammes of 
phosphorite in a soluble state, corresponding to 525 
million milligrammes (525 kilogrammes) of pure phos- 
phate of lime. 

As determined by direct experiments, 1 cubic deci- 
metre of Schleissheim soil absorbs 976 milligrammes of 
phosphate of lime. Each square decimetre received in 
the manure 525 milligrammes, which, dissolved by rain 
water in its descent through the soil, would be sufficient 
to saturate the earth fully, with phosphate of lime, to a 
depth of 5*4 centimetres (rather more than 2 inches), or 
to half-saturate it to a depth of 10*8 centimetres. Hence 
the manuring served to enrich the upper layer of the 
soil with phosphate of lime, not to the extent of rV^h, 
but to 50 per cent., and the greater part of this in a 
state available for the nutrition of plants. The absorj)- 
tive power of the soil explains, therefore, why the crops 
obtained from manured fields are rather in proportion to 
the nutritive substances supplied in the manure, than to 
the store of these elements originally present in the soil. 



OPEKATION OF MANURING AGENTS. 



151 



The operation of manuring agents, severally or 
jointly applied, is even more marked upon soils which 
are poorer in nutritive substances than the field at 
Schleissheim above mentioned. 

The following results were obtained on a field broken 
up for the purpose, which had not been touched by the 
plough for fifteen years, and had served as a pasture for 
sheep. The entire surface-layer of the ground at 
Schleissheim is C inches deep at most ; below this there 
is no more soil, but a bed of rubble stones, which might 
be compared to a sieve with meshes an inch wide, 
through M'hich the water runs freely ; the crop ob- 
tained from the unmanured portion will give some idea 
of its sterility. Another portion was manured with 
supei'phosphate of lime ; the quantity used per hectare 
( = 2-J- acres) was 525 kilogrammes ( = 10 cwt.) of 
phosphorite decomposed by sulphuric acid, containing 
193 kilogrammes of phosphoric acid, or •420 kilo- 
grammes ( = 8 cwt.) of phosphate of lime. 

Crop of winter-rye in 1858 at Schleissheim, per 
hectare : — 





Total crop. 


Corn. 


Straw. 


Manured with phosphor-' 
ite (rendered soluble 
by sulphuric acid) = 
625-3 kilo. (10 cwt.) 


Kilo. Cwt. 


Kilo, Cwt. 


Kilo. Cwt. 


containing 192-8 kilo. I 


1995-4 = 391-0 


654-2=128-0 


1341-2 = 200-0 


(3-8 cwt.) P Oo, corre- 








sponding to 420 kilo. 
(8 cwt.) of pure phos- 
phate of lime ^ 

Unmanured 


397-6= 7-8 


115-0= 2-3 


282-6= 5-5 



Dr. Zoeller found by analysis that- this field con- 
tained, per hectare, to a depth of 6 inches, only 727 
kilogrammes ( = 14 cwt.) of phosphoric acid. 

The plot manured with phosphoric acid produced 
six times more corn and five times more straw than the 
unmanured plot. It will be observed that, however 



152 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

strikingly the action of mannre was exMbited, this 
more abundant crop did not equal that in the experi- 
ment previously mentioned of the unmanured plot kept 
for a considerable time under culture. Upon compar- 
ing the amount of i)hosphoric acid contained in the two 
fields, we find that as the sheep pastures, to the depth of 6 
inches, contained only half as much as the other (tilled 
but unmanured), the dressing with supei'phosphate was 
only just sufficient to make the sheep-meadow, to the 
depth of 8 or 10 centimetres ( = 3 to 4 inches), equal 
to the other unmanured plot, in respect of the phosphoric 
acid contained in it. 

These considerations explain how it is that by the 
absorption of nutritive substances in the upjDcr layers 
of the soil a supply of these constituents or manuring 
ingredients, small in comparison to the total store in the 
ground, exercises so remarkable an action in the increase 
of produce, in the case of plants which draw their food 
chiefly from the upper layers of tlie arable surface soil. 

If the action of the mineral constituents depends 
upon the sum of effective particles in certain places in 
the soil, the action rises with the number of particles by- 
which the sum has been increased in these very places. 

A more accurate acquaintance with the composition 
of arable surface soil, and its relation to the nutritive 
substances, together with a consideration of the nature 
and requirements of plants, must gradually lead to a 
comprehension of many other phenomena in agriculture, 
which hitherto are quite unexplained, and to many 
farmers are absolute mysteries. Although we know 
most accurately the general laws of the growth of 
plants, as far as these stand in connection with soil, air, 
and water, yet in many cases it is extremely diflicult to 
discover the causes that render a soil unproductive for 
one culture-plant, e.g. peas, while the same soil is fruit- 
ful for other plants which require the same nutritive 
substances as peas, and often in still greater quantity. 
If the ground is rich enough in nutritive substances for 
these other plants, why is it that they do not act in the 
same way upon the peas ? What causes prevent the 



DimCULTIES NOT ALWAYS EXPLAINED. 163 

latter from appropriating the nutritive substances, 
whicli the ground oficrs to other plants in a perfectly 
available condition ? Finally, how comes it that this 
very soil, after a few years, will again yield a remune- 
rative crop of peas, although by intervening harvests 
we have rather impoverished than enriched its store of 
nutritive substances ; and that peas, when sown among 
oats, barley, or sunnner corn, will often yield a higher 
crop than when they grow alone upon a field, and have 
not to share with other plants the store of mineral con- 
stituents ? 

Analogous facts are observed in the cultivation of 
clover. In many districts, a field, after producing many 
clover crops, will become almost unfruitful for that 
plant. 

In such cases, manuring fails in restoring to the field 
the power of producing clover ; but after several years, 
during which the same field continues to give remu- 
nerative crops of cereal and tuberous plants, the soil 
again becomes for a while fruitful for clover. 

For a considerable number of our cultivated plants 
we have a pretty accurate knowledge of specific manur- 
ing agents, i.e. those which have a peculiarly favourable 
influence upon the majority of fields. Farm-yard ma- 
nure, as a rule, acts beneficially in all cases ; salts of 
ammonia are especially valuable for cereals, superphos- 
phate of lime for turnips ; bone earth and ashes will 
perceptibly increase the produce of fruitful clover-fields, 
and, in like manner, a supply of lime will often make a 
field fruitful for clover, though otherwise unable to 
bear it. 

But upon fields which have become, as it is termed, 
peas or clover sick, that is, have lost their power of pro- 
ducing these plants, all these matters otherwise favour- 
able for their growth exercise beyond a certain time no 
further beneficial action. It is this fact in particular 
which embarrasses the practical farmer, and makes him 
doul)t the lessons taught by science. 

AVhen the farmer is compelled to give up for many 
years the cultivation of plants wliich he had found re- 



154 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

munerative, and science has no power to help him over 
his difficulties, what is the use of theory ? So says the 
agriculturist who is himself unacquainted with the 
essence of theory. 

It is a common error to fancy that an accurate 
knowledge of theory will give the power of explaining 
all cases that occur. Theory of itself does not explain 
a single phenomenon in astronomy, mechanics, physics, 
or chemistry ; it studies and points out the causes which 
lie at the foundatioii of all phenomena, not the special 
causes upon which an individual phenomenon depends. 

Theory requires that the causes which govern each 
individual case should be sought out one by one, and 
then the explanation is the proof or exposition of the 
manner in which they work together to ])roduce the 
particular fact. It teaches us what to look for, and how 
to employ proper experiments in the discovery. 

The reason why we have arrived at no conclusions 
r''^out the facts just mentioned, depends chiefly upon 
this, that hitherto the practical farmer has troubled 
himself very little about the causes of those facts, as, 
indeed, the investigation of causes is not his proper 
business ; while those who have undertaken this task 
show, by the way in which they attempt to discharge 
it, that they are but little acquainted with the plant as 
an organised being, having peculiar requirements which 
must be accurately known by all w^ho Avould cultivate 
it properly. 

In the following remarks I shall compare a pea- 
plant with a cereal, and shall call the attention of agri- 
culturists to certain peculiarities which have to be con- 
sidered in the cultivation of both plants. 

A moderately moist, strong soil, not too cohesive 
and perfectly free from weeds, is particularly suited for 
peas and barley ; a well-tilled, calcareous loam or marl 
is the best for both plants. An arable surface soil 6 
inches deep suffices for barley, which, with its fine- 
matted roots spreading in tufts, finds a loose subsoil 
rather injurious than beneficial. Fresh manuring just 
before sowing acts powerfully on the growth of barley. 



GROWTH OF TEA AND BARLEY COMPARED. 155 

Whilst the barley-corn should not lie lower than an 
inch, the pea thrives best if the seed is put 2 or 3 inches 
deep in the soil. The roots of the pea-plant do not 
spread sidcAvays but go deep into the earth ; hence peas 
require a deep soil tilled down to the lower layers, and 
a loose subsoil. Fresh manure has scarcely any in- 
fluence ui)on the growth of i)eas. 

It results from these peculiarities of both plants, that 
the barley derives the conditions of its growth princi- 
pally from, the arable surface soil, the pea principally 
from the deeper layers of the soil. What the ground 
may contain below the depth of 6 inches is a matter of 
indifference for the barley ; the contents of these deeper 
layers are everything to the pea. 

If we now inquire what demands are made upon the 
soil by the two plants, we find from Mayer's investiga- 
tions (' Results of Agricultural and Chemical Experi- 
ments, Munich, 1857,' p. 35), that the pea-seeds contain 
one-third more ash constituents (3.5 per cent.) than the 
barley-corns, and that the amount of phosphoric acid is 
pretty much the same in both (2*7 per cent.). There- 
fore, all other conditions being equal, the subsoil from 
which the pea derives its phosphoric acid must be as rich 
in that ingredient as the arable surface soil which sup- 
plies it to the barley. 

The case is different with nitrogen — for the same 
amount of phosphoric acid, peas contain nearly twice as 
much nitrogen as barley. Assuming both plants to 
derive their nitrogen from the soil (which is, perhaps, 
not quite correct in the case of peas), then for every 
milligramme of nitrogen absorbed by the roots of the 
barley from the arable surface soil, twice as much must 
be received by the peas from the deeper layers. 

These considerations throw some light, I think, upon 
the cultivation of peas ; for this plant requires a very 
peculiar condition of the soil ; and it is more easy to 
conceive that a ground exhausted by bearing peas 
should refuse to bear any more, than that the same soil, 
after the lapse of some years, should again become fruit- 
ful for this plant. 



156 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

According to these considerations, and assuming an 
equality of the absorbent root-surface in both phmts, a 
subsoil fruitful for peas must contain as much phos- 
l^horic acid, and twice as much nitrogen, as an arable 
surface soil suited for the cultivation of barley. For 
the phosphoric acid, the assumption is correct. 

We understand, without difficulty, the beneficial 
efiPect of manui-e upon an exhausted barley field. Bar- 
ley derives all the conditions of healthy growth from 
the surface soil, which is restored to its original state of 
productiveness by the manure applied. 

But from our acquaintance with the properties pecu- 
liar to arable soil, we know that a layer 6 to 10 inches 
deep will retain all the annnonia potash and phosphoric 
acid contained in the largest quantity of manure usually 
applied by farmers ; and this, too, so firmly that, except 
for some accidentally favourable circumstances, hardly 
a particle will ever reach the subsoil. 

If a field is sown with plants which require deep 
ploughing, so that a sufficient portion of the rich sur- 
face is mixed with the exhausted subsoil, it is easy to 
understand that the latter may gradually become again 
fruitful for peas. The time in which this is eflTected 
depends of course upon the accidental selection of the 
plants grown in succession on the field. 

In this view of the matter, the agriculturist hns it in 
his power, by right management of his field, to shorten 
the time, and make the land again fit for successive 
crops of peas. 

It is a fact, that many fields in the vicinity of towns 
will bear year after year, or every two years,' abundant 
crops of peas, without ever becoming ' pea-sick ; ' and 
we know that the gardener, to achieve this result, has 
recourse to no extraordinary appliances, but merely tills 
his land deep and very carefully, using much more 
manure than the farmer can aflford to do. 

The frequent failure of peas is therefore not so very 
unaccountable ; and there seems no reason why the 
farmer should despair of cultivating peas as often as 
serves his purpose, if he employ the right means to 



A CLOVER-SICK FIELD. 157 

enrich his field in the proper spots with the elements 
of food which peas require. 

In all prublciiis of this kind, the secret of success is, 
not to sup})0se that the sohition is easy, but that it is 
attended Avith great dithculties ; for, if these did not 
exist, experimental art would long ago have found the 
solution. 

The many unsuccessful experiments of Messrs. Lawes 
and Gilbert to make a clover-sick field again productive 
for clover, have a certain value, in as far as they show 
that mere experimenting leads to nothing. If I here 
bestow upon these experiments an attention which they 
do not deserve, my object is, not to submit them to a 
passing criticism, but to warn the practical man how he 
ought not to proceed in trying to solve his problems, 
if he wishes that his efibrts should meet with success. 
The conclusions which Messrs. Lawes and Gilbert have 
drawn from their numerous experiments are as fol- 
lows : — they found that when land is not yet clover- 
sick, the crop may frequently be increased by manuring 
with salts of potash and superphosphate of lime ; that 
when, on the contrary, the land is clover-sick, none of 
the ordinary manures, whether ' artificial ' or ' natural,' 
can be relied upon to secure a crop ; and that the only 
way is to wait some years before repeating red clover on 
the same land. 

It is hardly necessary to remark, that what Messrs. 
Lawes and Gilbert are here pleased to call conclusions, 
are no conclusions at all ; what they have discovered 
has been experienced by thousands of agriculturists be- 
fore them ; and the only conclusion which they were 
permitted to draw should have been this — that in their 
attempts, by certain manures, to make a clover-sick 
field again productive for clover, they failed. In truth, 
they have not striven, in the remotest degree, to pro- 
cure information about the causes of clover-sickness in a 
field, but thev have simply tried different manures, in 
the hope of finding out one that niiglit serve to restore 
the original productive power of the field, and such a 
manure they have not found. 



158 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

Messrs. Lawes and Gilbert assume that, with respect 
to the soil, the clover plant bears the same relation as 
wheat or barley ; and finding that on a field (whereon, 
notwithstanding the richest mannre, clover had failed) 
an abundant barley or wheat crop was obtained the 
year after, it became a settled conviction with them 
that the failure of the clover had been caused by a spe- 
cific disease generated in the soil by the cultivation of 
clover ; this disease would attack the clover plant, but 
not the roots of wheat or barley. 

Clover differs entirely from the cereal plants in this 
respect, that it sends its main roots perpendicularly 
downwards, when no obstacles stand in the wa_y, to a 
depth which the fine fibrous roots of wheat and barley 
fail to reach ; the principal roots of clover (as may be 
seen more especially with Trifolium pratense) branch 
off into creeping shoots, which again send forth fresh 
roots downwards. 

Thus clover, like the pea-plant, derives its principal 
food from the layers below the arable surface soil ; 
and the difference between the two consists mainly in 
this — that the clover, from its larger and more exten- 
sive root-surface, can still find a sufficiency of food in 
fields where peas will no longer thrive : the natural 
consequence is, that the subsoil is left proportionably 
much poorer by clover than by the pea. 

Clover-seed, on account of its small size, can furnish 
from its own mass but few formative elements for the 
young plant, and requires a rich arable surface for its 
developement ; but the plant takes comparatively little 
food from the surface soil. When the roots have 
pierced through this, the upper parts are soon covered 
with a corky coating, and only the fine root-fibres rami- 
fying through the subsoil convey food to the plant. 

]Row, if we look at the experiments made by Messrs. 
Lawes and Gilbert to render a clover-sick field produc- 
tive again for clover, we see, at once, that all the means 
employed were well adapted to enrich the uppermost 
layers of their field with nutritive substances for wheat 
and barley ; but that the clover plant could derive ben- 



A CLOVEK-SICK FIELD. 159 

efit from this manuring only in the first stage of devol- 
openient, while the condition of the lower layers re- 
mained imaltered, just as if the field had received no 
nutriment of any kind. 

The manures applied by Messrs. Lawes and Gilbert 
were superphosphates of lime (300 lbs. of bone-earth 
and 225 lbs. of sulphuric acid per acre) ; sulphate of 
potash (500 lbs.) ; sulphate of potash and superphos- 
phate, mixed alkaline salts (500 lbs. of sulphate of pot- 
ash, 225 lbs. of sulphate of soda, 100 lbs. of sulphate of 
magnesia) ; mixed alkalis with superphosphate ; fur- 
ther, salts of ammonia alone, and the same salts with 
superphosphate or mixed alkalis ; farm-yard manure 
(15 tons), together with lime, or with lime and super- 
phosphate, or with lime and alkalis in the most varied 
proportions ; then soot ; soot with lime ; soot with 
lime, alkalis, and superphosphate. None of these ma- 
nures had the slightest effect ; the clover-sick field con- 
tinued just as unproductive for clover as before. 

The reason why these manures were inoperative is 
not difiicult to find. Messrs. Lawes and Gilbert, in 
their report, leave us, indeed, in the dark as to the na- 
ture and condition of the soil uj)on which their experi- 
ments were made ; but from some incidental observa- 
tions in previous papers, we know that the fields at 
Rothamstead consist of a rather heavy loam, very well 
suited for cereals, and especially for barley. 

From experiments upon the absorptive power of 
loam, WQ may assume, without risk of error, that one 
cubic decimetre (=61 cubic inches of loam) Avill absorb 
2000 milligrammes (=31 grains of potash), and 1000 
milligrammes (=15*5 of phosphate of lime). 

The surface of an acre of loam (=405,000 square 
decimetres) will therefore absorb to a depth of 1 deci- 
metre (=4 inches) 805 kilogrammes ( = 1,771 lbs.) of 
potash, and 405 kilogrammes (=891 lbs.) of phosphate 
of lime. 

The most copious dressing with sulphate of potash 
which Messrs. Lawes and Gilbert gave to their field 
amounted to 500 lbs. ( =270 lbs.) ot potash ; the most 



160 ACTION OF SOIL ON FOOD OF PLANTS IN SIANUEE. 

copious of the superpliospate dressings represented 300 
pounds of phosphate of lime. 

Had Messrs. Lawes and Gilbert put upon the field 
the sulphate of potash and the phosphate of lime in a 
state of complete solution, the whole quantity of potash 
employed would have penetrated no deeper than 2 cen- 
timetres, or not quite an inch, and the phosphate of 
lime no deeper than 4 centimetres, or a little more than 
1'6 inch. Both manures, however, were strewed over 
the field and ploughed in ; still it cannot be assumed 
that the layers below a dej^th of 8 inches could have 
received any considerable quantity of jjotash or phos- 
phate of lime. 

At page 10 of their paper (' Report of experiments 
on the growth of red clover by ditierent manures') 
Messrs. Lawes and Gilbert say, ' Those who have paid 
attention to the sj^read of disease in clover, on land 
which is said to be clover-sick, wull have observed, that 
however luxuriant the plant may be in the autumn and 
winter, it will show signs of failure in March or April.' 
The same fact was observed in all their experiments. 
A field on which clover had failed was sown with bar- 
ley, and when this had yielded a rich crop, another 
attempt was made with clover. 

' The plants (say Messrs. Lawes and Gilbert) stood 
tolerably well during the winter, but as the spring ad- 
vanced they died off rapidly,' There cannot be the 
slightest doubt about the reason of this decay ; the ex- 
hausted subsoil had not received back any of the lost 
conditions of fertility, and thus the plants were starved 
as soon as they had pushed through the arable surface 
soil, and their roots were beginning to spread in the 
subsoil. 

If the failure of the clover was attributable to a dis- 
ease, this must have been of a very singular nature, as 
the richly-manured arable soil showed no traces of it, 
and it was only the subsoil which was clover-sick. The 
notion that there is any disease engendered by the cul- 
tivation of clover is refuted most completely, though 
unconsciously, by Messrs. Lawes and Gilbert them- 



CArSE OF THE FAILURE OF CLOVER. IGl 

selves. They say, page 17, ' Before -we enter upon the 
probable causes of the failure in clover, it may be Avell 
to give the results of some experiments conducted in 
the kitchen-garden at Rothamstead. The soil was in 
ordinary garden cultivation, and has probably been so 
for two or three centuries. Early in 1854, the ^^r.th 
of an acre (about 9J square yards) was measured otf 
and sown with red clover on March 29. From that 
time to the end of 1859 fourteen cuttings have been 
taken without any resowing of seed. In 1856 this little 
plot was divided into three equal portions, of which one 
was manured with gypsum, another with sulphates of 
potash, soda, and magnesia, and superphosphate of 
lime,' 

' The estimated total amount of green clover ob- 
taied from this garden soil in six years, without further 
manure, is about 126 tons per acre, equal to about 26^ 
tons of hay. In four years the increase by the use of 
gypsnm amounted to 15|- tons of green clover. The 
increase in the four years by the use of the alkalis and 
phosphate is estimated to amount to 28f tons of green 
produce.' 

' It is worthy of remark,' continues the report, ' that 
it was in some of the very same seasons in which these 
heavy crops of clover were obtained from the garden 
soil, that we entirely failed to get anything like a mod- 
erate crop of clover in the experimental field, only a 
few hundred yards distant.' 

It is, indeed, most worthy of remark, that upon the 
experimental field tha earth was poisoned by the vege- 
tation of the clover, so as to render it incapable of fur- 
ther bearing this plant ; while, at the very same time, 
under like climatic conditions, the self-same clover-plant 
engendered no poison in the rich garden soil. 

A comparative examination of the garden and of the 
field-soil seems never to have been thought of, since the 
two agricultural chemists were, as we before remarked, 
in search of an efficient manure, not of the cause of the 
failure of the plant. But though they have not found 
the smallest shred of a fact which might serve in any 



162 ACTION OF SOIL ON FOOD OF PLANTS IN MANURE. 

waj to explain the strange behaviour of the clover-plant 
upon the two fields, they do not hesitate to present the 
fanner with the following ingenious explanation : — 

' Among plants,' say they, ' there are certain kinds 
which are peculiarly circumstanced with respect to the 
nature of their food ; the cereals, among others, feed 
principally upon inorganic matters, whilst others, the 
leguminous plants, e. g. clover, are dependent for luxu- 
riant growth, more or less, upon a supply within the 
soil of complex organic compounds.' 

Taking their stand upon the fact that they have 
failed to discover any explanation, which, in their 
opinion, they surely must have done, had it been pos- 
sible to find one, they coolly ask us to believe that 
there are, among the higher classes of plants, certain 
species bearing about the same relation to other species 
as the carnivorous to the graminivorous animals ; and 
as the former feed upon complex organic compounds 
prepared in the bodies of the latter, so it is, also, with 
the clover-plant ; like mushrooms, it represents the car- 
nivorous order in the veg-etable kingdom. 

It is hardly worth while to take any notice of this 
explanation ; but it might still prove useful to inquire 
whether, apart from all consideration of the absorj)tive 
power of the soil, Messrs. Lawes and Gilbert have really 
exhausted all the means that might have been employed 
to restore the productiveness of the clover-sick field for 
clover, so as to be justified in giving it as their opinion 
that when land is clover-sick, none of the ordinary ma- 
nures, artificial or natural, can be relied upon to secure 
a crop. 

We may ask why Messrs. Lawes and Gilbert did 
not, instead of superphosphate of lime, try bone ash, 
the action of which extends much deeper than that of 
the superphosphate ; and why sulphate of potash and 
sulphates alone were employed ? It is not impossible 
that common wood ashes might have proved more 
effective than sulphate of potash ; and, above all, chlo- 
ride of potassium ought to have been tried, which, as 
an ingredient of liquid manure, is more useful to clover 



EXPLANATION OF THE FAILURE OF CLOVER. 163 

than any" other of the potash salts. It is also difficult 
to understand wliy liquid manure AS'as not employed, 
and why chloride of sodium was excluded from the list 
of manuring agents. If we consider Avhat Messrs. 
Lawes and Gilbert omitted to do in their endeavour to 
solve the problem, and what they ought to have done, 
the conclusion is inevitable, that they had no accurate 
notion of the nature of their task. 

Now, the want of a jjroper insight into the nature 
of a phenomenon which is to be investigated is surely 
the greatest of all difficulties in the way of attaining a 
practical result. If the uni)roductiveness of a field for 
clover and peas depends upon a want of nitrogenous 
food in the deeper layers of the soil, and upon no other 
cause, the absorptive power of the various soils for am- 
monia renders it extremely difficult to enrich the sub- 
soil witli this element of food. But the case is quite 
different with the nitrates, which penetrate to any 
depth, as the nitric acid is not absorbed by the soil ; 
probably, nitrate of soda may afford a means of making 
a field productive for clover or peas, in cases where 
there is a deficiency of nitrogenous food. 

As manuring with bunit lime is often found bene- 
ficial for clover and also for peas, and a calcareous soil 
tends, in a special degree, to promote the formation of 
nitric acid, it is not improbable that it is owing to this 
property that lime promotes the growth of deep-rooting 
plants by converting ammonia into nitric acid, and 
causing nitrogenous food to find its way to the deeper 
layers of the soil. 



CHAPTER lY. 



FAKM-YAED MANURE. 

The fertility of a soil depends upon the sum of available food, the continuance of 
the fertility upon the total amount of all food in it — Chemical and agricultural 
exhaustion of the soil — Exhaustion of the soil hy cultivation, laws regulating 
its progression ; effect of tlie transformation in the soil of the chemically fixed 
into physically fixed elements'of food ; cll'ect on the progress of exhaustion by 
partial restoration of the withdrawn food of plants — Progress of the exhaustion 
by different cultivated plants — Cultivation of cereals, consequence of removing 
the grain and leaving the straw in the soil ; intervening clover and potato 
crops ; effect of leaving in the ground the whole or a portion of these crops ; 
division of soils ; productive power of wheat fields increased by accumulating 
in tliem the materials derived from clover and potato fields ; cultivation of 
fodder plants ; their food partly derived from the subsoil ; addition of these in- 
creases the productive power of the surface soil — Natural connection between 
the cultivation of cereals and fodder plants, the influence on the fertility of 
land— Exhaustion of the soil removed by the restoration of the withdrawn 
mineral constituents ; the excrenunt of men and animals contains these ; their 
restoration depends upon the agriculturist. 

TO form a correct idea of the effects produced by 
farm-yard manure in husbandry, it must be remem- 
bered that the fertility of a soil is always exactly pro- 
portionate to the amount which it contains of nutritive 
substances in a state of physical combination ; and that 
the permanence of its fertility or its productive power 
stands in proportion to the total quantity of the con- 
stituents in the soil capable of passing over into that 
physical condition. 

The amount of crop reaped from a field in a given 
time is proportionate to that fraction of the total con- 
stituents which has passed during this time from the 
ground into the plants grown upon it. If one of two 
fields yields twice as large a crop of wheat and straw as 
the other, this necessarily presupposes that the wheat- 
plants upon the one field have received from the ground 
twice as much nutriment as those upon the other. 



CHEMICAL AND AGKICTJLTUBAL EXHAUSTION. 1G5 

If the same or diflerent plants are cultivated in suc- 
cession on a field, the crops will gradually decrease, 
and the soil will be termed ' exhausted,' in an agricul- 
tural sense, when the crops cease to be remunerative, i e. 
do not cover the expense of labour, interest of money, 
etc. As the high crops were caused by the soil giving to 
the plant a certain number of parts from the total nutri- 
tive substances, just so the exhaustion of the field pro- 
ceeds from a diminution in the sum of those nutritive 
substances. 

The same number of plants cannot thrive upon the 
same field as formerly, if the same quantity of nutritive 
substances enjoyed by the previous crop is no longer to 
be found. The exhaustion of a cultivated field in a 
chemical sense differs from the agricultural use of the 
term in this, that the former refers to the total amount 
of nutritive substances in the soil, the latter to that 
portion only of the total amount which the ground can 
furnish to plants. A field is termed exhausted in a 
chemical sense when it altogether fails to produce any 
more crops. 

Of two fields, one of which contains, to the same 
depth, a hundred times, the other only thirty times, the 
amount of food required by a full wheat crop, the for- 
mer furnishes to the roots of the plants more nutriment 
than the latter in the proportion of 10 : 3, supposing 
the condition and mixture of the soil to be the same in 
both cases. If tlie roots of a plant receive from certain 
spots of the one field 10 parts by weight of nutriment, 
the roots of the same plant will find upon the other 
field only 3 such parts available for absorption. 

An average wheat crop of 2000 kilogrammes ( = 39 
cwts.) of grain, and 5000 kilogrammes ( = 98 cwts.) 
of straw, receives from a hectare ( = 2tV acres) of ground 
250 kilogrammes ( = 5 cwts.) of ash-constituents on, 
an average. Now, upon the supposition that a field, 
to give an average crop, must contain 100 times that 
quantity (or 25,000 kilogrammes) of asli-constituents in 
a perfectly available state, it follows that such a field 
gives 1 per cent, of its total store to the first crop. 



166 FAKM-YAED MANURE. 

The soil will still continue productive for new wheat 
crops in the following years ; but the amount of prod- 
uce will gradually decrease. 

If the soil is most carefully mixed, the wheat plants 
will, in the next year, find everywhere upon the same 
field 1 per cent, less nutriment, and the produce in corn 
and straw must be smaller in the same proportion. If 
the climatic conditions, the temperature, and the fall of 
rain remain the same, there will be reaped from the 
field in the second year only 1980 kilogrammes of grain, 
and 4950 kilogrammes of straw ; and in each succeed- 
ing year the crop must fall ofi" in a fixed ratio. 

If the wheat crop in the first year took away 250 
kilogrammes of ash-constituents, and the soil contained 
per hectare to the depth of 12 inches one hundred times 
that quantity (25,000 kilogrammes), there would remain 
in the ground at the end of the thirtieth year of culti- 
vation 18,492 kilogrammes of nutritive sulDstances. 

Whatever variations in the amount of produce 
may have been caused by climatic conditions during 
the intervening years, it is evident that in the thirty- 
first year, if there has been no restoration of mineral 
matters, the field will produce, even under the most 
favourable circumstances, only HI = 0-74, or some- 
what less than three-fourths of an average crop. 

If these three-fourths of an average crop do not give 
the farmer a sufiicient excess of income over expen- 
diture, if they barely cover his outlay, the crop can no 
longer be called remunerative. He calls his field ' ex- 
hausted ' lor the cultivation of wheat, although it con- 
tains seventy-four times the quantity of nutritive sub- 
stances required by an average crop for the year. 
Owing to the presence of the entire sum of nutritive 
substances, in the first year of cultivation each root 
found, in the parts of the soil in contact with it, the 
requisite amount of mineral food for its complete devel- 
opement ; but, owing to the continuous crops, only 
three-fourths of this quantity is found in the thirty- 
first year in the same portions of the soil. 

An average crop of rye (1600 kilogrammes ( = 31^ 



EEMUNERATIVE OAT CROP AFTEE RYE. 107 

cwts.) of grain, and 3800 kilogrammes ( = 74^ cwts.) of 
straw) takes away from the ground per hectare only 180 
kilogrammes ( = 3^ cwt.) of ash-eonstitnents. 

tf the production of an average wheat crop requires 
the presence in the soil of 25,000 kilogrammes of the 
ash-constitucnts of wlieat plants, a soil with only 18,000 
kilogrammes of such constituents will prove sufficiently 
rich^ to give an average and a succession of remunera- 
tive crops of rye. 

By our reckoning, a field, though exhausted for the 
cultivation of wheat, still contains 18,492 kilogrammes 
of mineral constituents, the same in properties as those 
which the rye plant requires. 

If it is asked after how many years continuous rye- 
cultivation the average crop will sink down to a three- 
quarter crop, assuming this to he no longer remunera- 
tive, we find that the field will produce 28 remunerative 
rye-crops, and after 28 years will he exhausted for its 
cultivation. 

Tlie nutritive substances yet remaining in the soil 
will still amount to 13,869 kilogrammes of ash-con- 
stituents. 

A field on which rye can no longer he cultivated 
with profit is not on that account unfruitful for oats. 

An average crop of oats (2000 kilogrammes ( = 39 
cwts.) of grain, and 3000 kilogrammes ( = 59 cwts.) of 
straw) takes from the soil 310 kilogrammes ( = 6 cwts.) 
of ash-constituents, being 60 kilogrammes ( = 1*2 cwt.) 
more than is removed by a wheat crop, and 130 kilo- 
grammes ( = 2^ cwts.) more than by a rye crop. If 
the absorbent root-surface of the oat plant were the 
same as that of rye, oats after rye would not yield a 
remunerative harvest ; for a soil supplying, for the 
production of a crop of oats, 310 kilogrammes out of a 
stock of 13,869 kilogrammes, loses thereby 2*23 per 
cent, of its store of mineral constituents, whereas the 
roots of rye extract only 1 per cent. 

To produce a remunerative crop of oats after rye is 
only possible when the root-surface of the oat plant 
exceeds that of the rye in the proportion of 2*23 to 1. 



168 FAEM-YAED MANTJEE. 

Oat crops will therefore exhaust the soil the most 
speedily ; after 12f years the harvest will sink to three- 
fourths of the original amount. 

None of the causes tending to diminish or increase 
the crops have any influence on this law of exhaustion 
of the soil by cultivation. Whenever the stock of nu- 
triment has been lowered to a certain point, the ground 
ceases to be productive, in an agricultural sense, for 
cultivated plants. 

For every cultivated plant such a law exists. This 
state of exhaustion will inevitably take place, even 
though only a single one of the various mineral con- 
stituents required for the nutrition of the plants has 
been withdrawn from the soil by a succession of crops ; 
for the one constituent which fails or is deficient ren- 
ders all the rest ineffective. With each crop, each 
plant, or portion of a plant, taken away from a field, 
the soil loses part of the conditions of its fertility, that 
is, after a course of years of cultivation it loses the 
power of again producing this crop, plant, or part of a 
plant. A thousand grains of corn require from the soil 
a thousand times as much phosphoric acid as one 
grain ; and a thousand straws demand a thousand 
times as much silicic acid as one straw. When, there- 
fore, the soil is deficient in the thousandth part of 
phosphoric or silicic acid, the thousandth grain or 
the thousandth straw will not be formed. If a single 
stalk of corn is taken away from a field, the conse- 
quence is that the field no longer produces one straw 
in its room. 

Hence it follows that a hectare of ground, contain- 
ing 25,000 kilogrammes of the ash-constituents of 
wheat, uniformly distributed, and presented to the 
roots of the plants in a perfectly available condition, 
can, up to a certain point, continue to give in succes- 
sion remunerative crops of various cereal plants, with- 
out receiving any restoration of the mineral constitu- 
ents taken away in the corn and straw, provided that 
the uniform mixture of the soil be maintained by care- 
ful ploughing and other suitable means. The succes- 



UNEQUAL DISTRIBUTION OF FOOD IN SOILS. 169 

sion of crops is determined by this principle, that the 
second plant must always take away from the soil less 
than the lirst, or possess a g-reatcr number of roots, or 
generally a larger absorbent root-surface. After the 
average cM'op of the lirst year, the crops would go on 
yearly diminishing. 

The farmer, to whom uniform average harvests are 
the exception, and an alternation of good and bad crops 
dependent upon change of weather is the rule, would 
hardly notice this constant diminution, even supposing 
liis field to be actually in that favourable chemical and 
physical condition which would enable him to cultivate 
wheat, rye, and oats for seventy years in succession, 
without restoring any of the mineral constituents re- 
moved from the soil. Good crops approaching the 
average in favourable years, would alternate with defi- 
cient c)"Oj)s in bad seasons ; but the proportion of un- 
favourable to favourable returns would go on in- 
creasing. 

Most of the land under cultivation in Europe is not 
in the physical condition assumed in the case of the 
field which we liave been considering. 

In most fields the phosphoric acid required by the 
plants is not all distributed in an efi'ective condition, 
and accessible to the roots ; a part of it is merely dis- 
seminated through the soil in the form of small gran- 
ules of apatite (phosphate of lime) ; and even where the 
soil contains altogether a quantity more than sufficient, 
yet in some parts of it there is much more and in 
others less than the plants require. 

If we suppose our field to contain 25,000 kilo- 
grammes of the ash-constituents of wheat equally dis- 
tributed through the soil, and five, ten, or more thou- 
sand ])ounds of the same constituents, unequally dis- 
tributed, the phosplioric acid as apatite, the silicic acid 
and potash as decomposable silicates ; and, further, if 
every two years a certain quantity of this second por- 
tion of food elements becomes, in the manner stated, 
soluble and di.striluitable, so that the roots of plants in 
all parts of the arable soil could find as much of these 

8 



170 FAEM-YAKD MANUKE. 

nutritive substances as in the preceding years of culti- 
vation — suflScient, tlierefore, for an average crop ; we 
should, in that case, be able to obtain full average 
crops for a number of years by always letting a year 
of fallow intervene after a year of cultivation. Instead 
of thirty progressively decreasing crops, we should in 
that case reap thirty full average crops in sixty years, 
if the excess of mineral matter in the soil were suffi- 
ciently large to replace everywhere the phosphoric 
acid, silicic acid, and potash taken away in each year 
of crops. After the exhaustion of this excess of min- 
eral matter, the period of diminishing crops would com- 
mence for our Held, and the interposition of fallow 
years would, after this, no longer exercise the least in- 
fluence on the production of larger crops. 

If the excess of phosphoric acid, silicic acid, and 
potash, which we have assumed in the case under con- 
sideration, wei-e not unequally but uniformly distrib- 
uted, and everywhere perfectly accessible and available 
to the roots of the plants, our field would be able to 
yield thirty full average crops in thirty successive 
years, without the intervention of a season of fallow. 

Let us return to our field, which we have assumed 
to contain 25,000 kilogrammes of the ash-constituents 
of wheat, equally distributed through the soil, and in a 
suitable state for absorption by the roots. Suppose we 
were to cultivate wheat upon it year after year, but in- 
stead of removing the entire crop we were merely to 
cut off the ears, leaving the straw on the ground and 
immediately ploughing it in ; the loss sustained by the 
field would, in this case, be less than before, as all the 
constituents of the straw and the leaves would be left 
in the field, the mineral constituents of the grain alone 
having been removed. 

The straw and leaves contain, among their constitu- 
ent elements, the same mineral substances as the grain, 
only in different proportions. If the total quantity of 
phosphoric acid conveyed away in the straw and corn 
be designated by the number 3, the loss will be only 2, 
if the straw is left in the ground. The decrease of 



RETARDATION OF THE PERIOD OF EXHAUSTION. 171 

produce from the field, in the following year, is always 
ill proportion to the loss of mineral substances occa- 
sioned by the prccediug crop. The next produce of 
grain will be a little larger than it would have been 
had the straw not been left in the ground ; the produce 
of straw will be nearly the same as in the preceding 
year, because the conditions ibr the formation of straw 
have been but slightly altered. 

Thus, then, by taking away from the ground less 
than foi-merly, we increase the number of remunerative 
crops, or the sum total of grain produced in the whole 
series of corn harvests. Some of the straw-constituents 
are converted into corn-constituents, and are now re- 
moved from the field in the latter form. The period 
of final exhaustion, though sure to come in the end,' 
will, under these circumstances, occur later. The con- 
ditions for the production of grain go on continually 
decreasing, because the substances removed in the corn 
are not replaced. 

It would make no difference in this respect, if the 
straw were cut and carted about the field, or used as 
litter for cattle and then ploughed in ; the supply thus 
bestowed upon the field, having been originally taken 
from the field, cannot enrich it. 

Considering that the combustible elements of the 
straw are not supplied by the soil, it is clear that in 
leaving the straw in the ground we leave nothing more 
than the ash-constituents of the straw. The lield re- 
mained somewhat more fruitful than before, because a 
little less had been taken away. 

If the corn or its ash-constituents were ploughed in 
with the straw, or if, instead of it, a corresponding 
quantity of some other seed containing the same ash- 
constituents as wheat, e. g. ground rape-cake, that is, 
rape-seed freed from the fatty oil, were given in ])roper 
proportion to the ground, its composition would remain 
the same as before : the next year's crop Avould ecpial 
that of the preceding year. If after every harvest the 
straw is always in this manner returned to the field, 
the further consequence will be an inequality in the 



172 FAEM-YAED MANURE. 

composition of the effective constituents in tlie arable 
soil. 

We have supposed our field to contain the ash-con- 
tituents of tlie entire wheat plant in proper proportion 
for the formation of straw, leaves, and grain. By leav- 
ing the straw-constituents in the ground while continu- 
ally removing the grain-constituents, the former will 
accumulate and grow out of due proportion to the 
remainder of the grain-constituents still contained in 
the field. The field retains its fertility for straw, but 
the conditions required for the production of grain are 
diminished. 

The consequence of this disproportion is an unequal 
developement of the entire plant. As long as the soil 
contained and supplied the right proportion of nsh-con- 
stituents needful for the uniform growth of all parts of 
the plant, so long the quality of the seed and the ratio 
between straw and corn in the diminishing crops re- 
mained constant and unaltered. But, in proportion as 
the conditions for the production of leaves and straw 
became more favourable, the quality of the grain dete- 
riorated with its decreasing quantity. The distinctive 
mark of this inequality in the soil, resulting from cul- 
tivation, is a decrease in the weight of the bushel of 
corn reaped from the field. At first a certain quantity 
of the constituents restored to the soil in the straw 
(phosphoric acid, potash, magnesia), was expended in 
the formation of grain ; but afterwards the case is re- 
versed, and the grain-constituents (phosphoric acid, 
potash, magnesia) are drawn upon for the production 
of straw. The condition of a field is conceivable where 
by reason of inequality in the relative conditions for 
producing straw and grain, under temperature and 
moisture favourable for the formation of leaves, a 
cereal plant may yield an enormous crop of straw, 
with empty ears. 

The farmer, in cultivating his plants, can act upon 
the direction of the vegetative force only through the 
soil, i. e. by supplying his field with nutritive sub- 
stances, in the right proportions. For the production 



EXHAUSTION OF A WHEAT SOIL. 1<3 

of the largest crop of grain, the soil must contain a 
preponderating quantity of the nntiitive snbstanccs 
necessary for tlic formation of seed. For leafy plants, 
turnips, and tuberous plants, the ])roportion is revors-ed. 

It is therefore evident, that it' on our field contain- 
ing 25,000 kilogrammes of the ash-constituents of the 
wheat-plant, we cultivate potatoes and clover, and take 
away from the field the entire crop of tubers and clo- 
ver, we remove from the ground, in these two products, 
as much phosphoric acid and three times as much ]:)ot- 
ash as in three wheat crops. It is certain that the ab- 
straction of these important mineral constituents from 
the ground, by the cultivation of another plant, must 
greatly affect the fertility of the soil for wheat ; the 
crops of wheat diminish in amount and in number. 

But if, instead of this, wc were to cultivate on our 
field alternately, wheat one year, potatoes the next, 
leaving the entire potato crop, tubers included, and the 
wheat straw on the ground to be ploughed in, and if 
this alternation of crops were continued for sixty years, 
the crop of corn which the field was originally capable 
of yielding would not in the slightest degree be altered 
or increased. The field would gain nothing by the 
cultivation of potatoes ; and would lose nothing, be- 
cause the whole crop was left in the soil. When by 
taking corn crops from the field, the store of mineral 
constituents had been reduced to three-fourths of the 
original quantity, the field would cease to furnish re- 
munerative crops, supposing that three-fourths of an 
average hardest leave no margin of profit for the far- 
mer. The same results would follow, if instead of po- 
tatoes we interpose clover, and constantly ploughed it 
in. We have assumed the field to be in the best phys- 
ical condition, which therefore could not be improved 
by the incorporation of the organic substances of the 
clover and the potatoes. Even if we were to take the 
potatoes from the field, to mow down and dry the clo- 
ver, giving both to cattle in the farm-yard or making 
any otlier use of them, and tlien to bring all back to 
the field and plough them in, so as to restore to the 



174 



FAEM-YAED MANUEE. 



soil all the mineral constituents contained in both crops, 
yet by all these operations the field would not produce, 
in thirty, sixty, or seventy years, a single grain of corn 
mure than without this alternation. The conditions 
required for the production of grain are not improved 
in the field during the whole of this period, and the 
causes of decrease in the crops remain the same. 

The ploughing in of the potatoes and the clover 
could have a bencificial effect upon those fields only 
which have an inferior physical condition, or in which 
the mineral constituents are unequally distributed, or 
are partially inaccessible to the roots of plants. But 
this eftect is like that of green manuring, or of one or 
more years of fallow. 

By the incorporation of the clover and the organic 
constituents with the soil, its store of decaying sub- 
stances and nitrogen increased year by year. All that 
these plants received from the atmosphere remained in 
the ground ; but the increase of these otherwise so use- 
ful substances cannot make the soil produce a larger 
amount of grain than before ; since the production of 
grain depends upon the right proportion of ash-constit- 
uents in the soil, and these, so far from being increased, 
have been gradually reduced by the removal of the 
corn crops. The augmentation of nitrogen and of de- 
caying organic substances in the soil might j)ossibly 
lead to an increase of produce for a number of years ; 
but the period when this field will cease to give remu- 
nerative crops will in that case come all the sooner. 

If we take three wheat fields, and cultivate wheat 
upon the one, potatoes and clover upon the other two ; 
and suppose we remove the corn alone from the wheat 
field and heap upon it and plough in all the crop of 
clover and all the potato tubers, then the wheat field 
will be more fertile than before, for it has been en- 
riched by all the mineral constituents which the two 
other fields had furnished to the potatoes and the clo- 
ver. It has received three times as much phosphoric 
acid and twenty times as much potash as was contained 
in the corn crop it produced. 



GRADUAL EXHAUSTION OF A WUEAT SOIL. 175 

This wheat field will now be able to produce three 
full corn crops in throe successive years, because the 
conditions for tlie formation of straw have remained 
unaltered, while those for the ])roduction of g;rain have 
been increased three-fold. If the farmer by this method 
raises as much corn in three years as he could obtain 
from the same fields in five years without the addition 
and cooperation of the constituents contained in the clo- 
ver and the potatoes, it is clear that his profit has been 
greater, since with three seed-corns he has obtained as 
good a harvest as in the other case with five. But 
what the wheat field has gained in fertility, the other 
two fields have lost ; and the final result is, that at less 
cost of cultivation, and with more profit than before, 
his three fields are brought to the period of exhaustion 
which inevitably results from the continued removal of 
the mineral constituents in the crops of corn. 

The last case which we have to consider is when 
the farmer, instead of growing potatoes and clover, cul- 
tivates turnips and lucerne, which by their long pene- 
trating roots extract a great quantity of mineral con- 
stituents from the subsoil, to which the roots of the 
cereals very seldom penetrate. When the fields have 
a subsoil favourable to the growth of these plants, it is 
as thougli the arable surface soil were doubled. If the 
roots of these plants receive the half of their mineral 
nutriment from the snbsoil, and the other half from the 
arable surface soil, the latter will lose by these crops 
only half as much as they would, if all the mineral con- 
stituents had been drawn by them from the surface. 

Tims the subsoil, considered as a field apart from 
the arable soil, gives to turnips and lucerne a certain 
quantity of mineral constituents. Now, if the whole 
of the turnip and lucerne crops were ploughed in dur- 
ing the autumn in a wheat field which had yielded an 
average crop of wheat, so that the field should receive 
back more than it had lost in the corn, it is clear that 
this field might be maintained in an equable state of 
fertility, at the expense of the subsoil, just so long as 
the latter remained productive for turnips and lucerne. 



176 FARM-YARD MANURE. 

As, however, turnips and Incerne require for their 
developement a very great quantity of mineral constitu- 
ents, the subsoil is so much the sooner exhausted, when 
it contains fewer of such constituents. Kow as it is 
not actually severed fj-om the arable surface, but lies 
underneath, it can scarcely regain any of all the con- 
stituents which it has lost, because the surface soil in- 
tercepts and retains the portion supplied. Only that 
part of the potash, ammonia, phosphoric acid, and 
silicic acid, which is not taken up and iixed by the sur- 
face soil, can reach the subsoil. 

It is therefore possible, by the cultivation of these 
deep-rooting plants, to gain an abundant supply of nu- 
tritive substances for all plants drawing their nutriment 
chiefly from the arable soil ; but this supply is not last- 
ing, and in a comparatively short time many fields will 
cease to bear crops, because tlie subsoil is exhausted, 
and its fertility is not easily restored. 

If a farmer grows upon three fields, potatoes, corn, 
and vetches or clover, alternately, or if he cultivates 
one field M'ith potatoes, corn, and vetches successively, 
selling the crops, and going on in the same way for 
many years, without manuring, any one can foresee 
the end of such husbandry, because such a system can- 
not possibly last. No matter what plants may be 
selected, what variety of cereals, tuberous or other 
plants, or in what rotation, the field will at length be 
reduced to such a state that the cereals will yield no 
more than the seed sown, the potatoes will give no 
tubers, and the vetches or clover will die away after 
barely appearing above ground. 

From these facts it follows indisputably, that there 
is no plant which spares the ground, and none which 
enriches it. The practical farmer is taught by innu- 
merable instances that the success of a second crop de- 
pends upon the previous one, and that it is by no 
means a matter of indifference, in what order he culti- 
vates his plants ; by previously cultivating some plant 
with extensive ramification of roots, the soil is made 
fitter for the growth of a succeeding cereal, which will 



A SECOND CROP DEPENDS ON THE PRECEDING ONE. 177 

DOW thrive better, even -without the application of ma- 
nure (with sparing application), and yield a richer crop. 
But this is not a saving of manure for future crops, nor 
has the field been enriched in the conditions of its fer- 
tilitv. There has been an increase, not in the sum of 
the nutriment, but in the available particles of that 
sum, and their operation has been hastened in point of 
time. 

The physical and chemical condition of the field 
was improved ; but the store of chemical elements was 
reduced. All plants, without exception, drain the soil, 
each in its own way, and exhaust the conditions for 
their reproduction. 

In the produce of his field the farmer actually sells 
his land ; he sells, in his crops, certain elements of the 
atmosphere, which come of themselves to his soil ; and 
with them certain constituents of the ground, which 
are his property, and which have served to form, out 
of the atmospheric elements, the body of the plant, 
being themselves coni])onent parts of that body. In 
alienating the crops of his field, he robs the land of the 
conditions required for their reproduction. Such a 
system of husbandry may properly be called a system 
of spoliation. 

The constituents of the soil are the farmer's capital ; 
the atmospheric nutritive substances are the interest of 
his capital ; M-ith the former he produces the latter. 
In selling the produce, he alienates part of his capital 
and the interest ; in restoring the constituents of the 
soil to the ground, he retains his capital. 

Common sense tells us, and all farmers agree, that 
clover, turnips, hay, &c., cannot be sold off from a 
farm without materially damaging the productive 
power of the land for corn. 

Everyone willingly admits, that the removal of clo- 
ver is prejudicial to the cultivation of corn ; but that 
the removal of corn should injure the cultivation of 
clover is to most farmers an inconceivable, nay, an im- 
possible idea. 

Yet the natural connection and mutual relations 



178 FAEM-TAED MANUEE. 

between the two classes of plants are as clear as day- 
light. The ash-constituents of clover and corn are the 
conditions for the formation of clover and corn, and are 
identical as far as the elements are concerned. 

Clover, just like corn, requires for its production a 
certain amount of phosphoric acid, potash, lime, and 
magnesia. The mineral constituents of clover are the 
same as those of corn, plus a certain excess of potash, 
lime, and sulphuric acid. The clover draws these con- 
stituents from the soil, the cereal plants may be repre- 
sented as deriving them from the clover. In selling 
his clover, therefore, the farmer takes away the condi- 
tions for tlie production of corn, and there remains be- 
hind in the soil less nutriment for the corn ; if he sells 
his corn, he takes away from the land some of the most 
indispensable conditions for the production of clover, 
hence the clover crop fails in the subsequent year. 

The peasant knows the operation of these fodder- 
plants, and expresses his views in his own way when 
he says, ' that, as a matter of course, a man must not 
sell his manure, without which no permanent cultiva- 
tion is possible, and that in selling the fodder-plants, a 
man sells his manure.' But that in selling his corn, a 
farmer is still parting with his manure, does not seem 
to be understood by many even of the most enlightened 
agi'iculturists. Farm-yard manure contains all the min- 
eral constituents of fodder ; and these consist of the 
constituents of corn, plus a certain quantity of potash, 
lime, and sulphuric acid. It is quite evident, that as 
the whole dung-heap consists of parts, not one of those 
parts should be alienated ; and if it were possible, by 
any means, to separate the corn-constituents from the 
rest, they would possess the greatest value to the far- 
mei', because upon them the cultivation of the corn 
depends. But this separation actually takes place in 
the growth of corn, as the mineral constituents of the 
manure become the constituents of the corn ; hence in 
selling the corn, the farmer alienates a portion, and 
indeed the most efficient portion, of his manure. 

Two dung-heaps, looking quite alike, and apparently 



COKN SOLD IS MANURE LOST. 179 

of the same quality, may yet have u ver^- dissimilar 
value for the cultivation of corn. If in one heap the 
ash-constituents of corn arc twice as many as in the 
other, the former has double the value of the other. 
By the removal of the mineral constituents of tlie corn, 
which were derived from the manure, the efficacy of 
the nnmure with regard to future corn crops is con- 
stantly diminished. 

From whatever ])oint of view, therefore, the aliena- 
tion of corn or other field produce maybe regarded, the 
farmer who does not rei)lace the mineral constituents 
taken away in the crops, will find that the inevitable 
result is exhaustion of the soil. Continued removal of 
the corn crops makes the ground unproductive for clo- 
ver, or deprives the manure of its efficacy. 

In our exhausted fields tlie roots of cereals no longer 
find, in the upper layers of the soil, sufficient nutriment 
for the production of a full crop : the farmer, therefore, 
grows on these fields clover, turnips, and other plants 
of the kind, which, with their wide-spreading ancl deep 
roots, penetrate in all directions through the soil, open 
up the ground by their large root-surface, and appro- 
priate the constituents which are needed by cereals for 
the formation of seed. In the lesidue of these plants, 
in the constituents of the stalks, the roots and the 
tubes, which the farmer puts upon the arable surface in 
the form of manure, he restores to the land, in a con- 
centrated form, the corn-constituents for one or several 
full crops : what was below and scattered, is now above. 
The clover and the fodder-plants did not engender the 
conditions of richer corn-crops, any more than rag- 
gatherers produce the conditions for paper-making : 
they are mere collectors. 

From the foregoing rcnuirks it is evident that the 
cultivation of plants exhausts the fertile soil, and ren- 
ders it unfruitful. In selling the produce of his fields, 
which serves as food for man and beast, the farmer re- 
moves a portion of his soil, and indeed the constituents 
most efficient for the ])roduction of future crops. In 
course of time, the fertility of his fields will decrease, 



180 FARM-YARD MANURE. 

no matter what plants he cultivates, or what order of 
rotation he may adopt. The removal of his crops is 
nothing else than robbing the ground of the conditions 
for future harvests. 

A field is not exhausted for corn, clover, tobacco, or 
turnips, so long as it yields remunerative crops, with- 
out needing the replacement of those mineral constitu- 
ents which have been carried away. It is exhausted 
from the time that the hand of man is needed to restore 
the failing conditions of its fertility. In this sense 
most of our cultivated fields are exhausted. 

The life of men, animals, and plants is most inti- 
mately connected with the restoration of all those con- 
ditions which cause the vital process to go on. The 
soil, by its constituents, takes part in the life of the 
plant ; its permanent fertility is inconceivable and im- 
possible, without the replacement of those conditions 
which have made it productive. 

The mightiest river which sets in motion thousands 
of mills and machines must fail, if the streams and 
brooks supplying its waters run dry ; so, too, the 
streams and brooks will run dry if the many little 
drops of which they consist fail to return in the form 
of rain to the place whence their sources spring. 

A field which, by the successive cultivation of 
difi'erent plants, has lost its fertility, may recover the 
power of yielding a new series of crops of the same 
plants, by the apphcation of manure. 

What is manure, and whence comes it ? All ma- 
nure comes from the farmer's fields : it consists of 
straw, which has served as litter ; of remains of plants, 
of the liquid and solid excrements of men and animals. 
The excrements are derived from food. 

In his daily bread, man consumes the ash-constitu- 
ents of the grain from the flour of which bread -is 
made : in meat he consumes the ash-constituents of 
flesh. 

Tlie flesh of herbivorous animals, and its ash-con- 
stituents, are derived from j^lants ; these ash-constitu- 
ents are identical with those of the seeds in leguminous 



MUTIJAL KELATION OF PLANTS AND ANIMALS. 181 

plants. Hence if an entire animal is burnt to ashes, 
the residue will differ little from the ashes of beans, 
lentils, and peas. 

In bread and flesh, therefore, man consumes the 
ash-constituents of seed, or of seed-constituents "which 
the farmer has obtained from his fields in the form of 
flesh. 

Of the large amount of mineral substances which 
man consumes in liis food during a lifetime, but a small 
fraction remains in his body. The body of an adult 
does not increase in weight from day to day, which 
proves that all the constituents of his food must com- 
pletely pass out again from his system. 

Chemical analysis demonstrates that the excrements 
of man contain the ash-constituents of bread and flesh 
very nearly in the same quantity as they exist in the 
food, which in the body undergoes a cliauge similar to 
that which would take place in a furnace. 

The urine contains the soluble, the solid excrements 
the insoluble ash-constituents of food : the stinking sub- 
stances are the smoke and soot of an imperfect combus- 
tion. With these are mixed up the undigested and the 
indigestible remains of food. 

The dung of swine fed on potatoes contains the ash- 
constituents of the potato ; that of the horse, the ash- 
constituents of hay and oats ; that of cattle, the ashes 
of turnips, clover, and other plants which have served 
them as food. Farm-yard manure comprises a mixture 
of all these excrements. 

That farm-yard manure will completely restore the 
fertility of a field exhausted by cultivation is a fact 
fully established by the experience of a thousand years. 

Farm-yard manure supplies to the field a certain 
quantity of organic, i. e. combustible substances, to- 
gether with the ash-constituents of the food consumed. 
"We must now consider what part is taken, in the 
restoration of fertility, by the combustible and incom- 
bustible constituents of the manure. 

The most superficial examination of a cultivated 
field shows that all the combustible constituents of the 



182 FAEM-YAED MANURE. 

plants grown upon it are derived from the air and not 
from the soil. If the carbon even of a portion of the 
vegetable matter in the crop were derived from the 
soil, it is quite clear, that if the ground contained a 
certain amount of carbon before the harvest, this 
amount must be smaller after every harvest. A soil 
deficient in organic matter must necessarily be less 
productive than a soil abounding in it. 

ISTow, experience proves that a field in constant cul- 
tivation does not, therefore, become poorer in oi'ganic 
or combustible substances. The soil of a meadow 
which in ten years has yielded a thousand cwt. of hay 
per hectare, is found to be, at the end of those ten 
years, not poorer in organic substances, but richer than 
before. A clover-field after a crop retains in the roots 
left in the ground more oi'ganic substances, more nitro- 
gen, than it originally possessed ; yet after a number 
of years it becomes unproductive for clover, and no 
longer gives remunerative returns of that crop. 

A field of wheat, or potatoes, is not poorer in or- 
ganic substances after harvest, than before. As a gen- 
eral rule, cultivation increases the store of combustible 
constituents in the ground, while its fertility, however, 
steadily diminishes. After a consecutive series of re- 
munerative crops of corn, turnips, and clover, these 
plants will thrive no longer in the same field. 

Since, then, the presence of decaying organic re- 
mains in the soil does not, in the slightest degree, pre- 
vent or arrest its exhaustion by cultivation ; it is im- 
possible that an increase of those substances can restore 
the lost capacity of a field for production. In fact, 
when a field is completely exhausted, neither boiled 
saw-dust nor salts of ammonia, nor both combined, will 
impart the power of yielding the same series of crops a 
second and third time. When these substances im- 
prove the physical condition of the ground, they exert 
a favourable influence upon the produce ; but, after all, 
their ultimate efi'ect is to accelerate and complete the 
exhaustion of the soil. 

But farm-yard manure thoroughly restores to the 



MINERAL MATTERS RESTORED BY MAN. 183 

soil the power of producing the same succession of 
crops a second, a third, and a hundredth time : wlicro 
it is applied in proper quantities it will fully cure the 
state of exhaustion, and often make a field more fertile 
than it ever was before. 

The restoration of fertility by farm-yard manure 
cannot be attributed to the mixture of combustible 
materials (salts of ammonia and the substance of decay- 
ing saw-dust) : for if these had a favourable efiect, it 
must have been of a subordinate kind. The action of 
farm-yard manure most undoubtedly depends upon the 
incombustible ash-constituents of the plants which it 
contains. 

In farm-yard manure the field actually receives a 
certain quantity of all the mineral ingredients which 
have been removed in the crops. The decline of fertil- 
ity was in proportion to the removal of mineral con- 
stituents ; the renewal of productiveness is in propor- 
tion to their restoration. 

The incombustible elements of cultivated plants do 
not of themselves return to the soil, as the combustible 
elements return to the atmosphere from which they 
spring. The hand of man alone restores to the ground 
the conditions of the life of plants : in fiirm-yard ma- 
nure wherein they are contained, the farmer, following 
a natural law, restores the lost power of production. 



CHAPTER V. 

THE SYSTEM OF FAKM-YAED MANURING. 

Questions to be solved— Experiments of Renninti, their significance — Produce of 
unmanured lields— Inllucnce of precedins crops', of tlie situation, and climatic 
conditions, on the produce— Each lield possesses its own power of production 
— Large crops, their dependence and continuation— Closeness of the food of 
plants, wliat is meant thereby— The closeness of the particles of food in the 
soil is in proportion to the produce— Produce of corn and straw influenced by 
the relations of the assimilated food and by the conditions of growth ; action 
of food supplied in manures— Potatoes, oats, and clover crops of the Saxon 
fields , conclusions drawn from them as to the condition of the fields- Produce 
of these fields from farm-yard manure ; the increase of produce cannot be cal- 
culated from the amount of manure used— Restoration of the power of produc- 
tion of exhausted fields by the increase of the necessary elements of food pre- 
sent in the soil in minimum amount ; advantageous use of farm-yard manure 
in this respect ; explanation of the result- Action of manure as compared with 
quantity used experiments — Rational system of cultivation — Depth to which 
the food of plants penetrates is dependent on the power of absorption of the 
eoil ; the Saxon fields considered in this respect ; the power of absorption con- 
sidered in manuring — Change produced in the composition of the soil by the 
system of farm-yard manuring; the different stages of this system, the final 
result — Examples of these stages in the Saxon experimental fields- Cause of 
the growth of weeds ; remedies — The history of husbandry, what is taught by 
it — Present condition of European husbandry — Present production of the land 
compared with the earlier , conclusions — Continuation of production regulated 
by a natural law — Law of restoration ; defective practice of it — Agriculture in 
the time of Charlemagne — Agriculture in the Palatinate — Corn fields in the 
valleys of the Nile and Ganges , nature provides in them for the restoration of 
food of plants — Practical agriculture and tlielaw of restoration — The statistical 
returns of average crops afford an explanation of the condition of corn fields. 

THE general observations in the preceding chapters 
on the mutual relations between the soil and plants, 
as also on the sources and nature of farm-yard manure, 
will, I hope, enable the reader to enter upon a thorough 
investigation of all those phenomena which are pre- 
• scnted by the practice of farm-yard manuring. We 
have to consider how farm-yard manure increases the 
produce of a field ; on which constituents of the 
manure its action depends ; what quantity of farm-yard 
manure can be obtained from a field ; and to what con- 



QUESTIONS TO BE CONSIDERED. 185 

dition, after a series of years, a field can be restored by 
farm-yard maiiiiriiig. 

It will be understood that iroiu this investigation 
we exclude all those etfects of farm-yard manure wliich 
cannot be determined by measure and number ; such, 
for instance, as its influence upon the looseness or cohe- 
sion of the soil, and its heating action, by means of the 
warmth resulting from the decay of its constituents in 
the ground. 

The facts, to which this investigation extends, are 
derived from practical experience ; and my selection of 
them has been materially facilitated by the comprehen- 
sive series of experiments made in the year 1851, at the 
instance of Dr. Rennikg, Secretary-General of the 
Agricultural Society in the kingdom of Saxony, by a 
number of Saxon agriculturists, with a view of ' ascer- 
taining the action of so-called artificial manures under 
every variety of condition, for the purpose of more gen- 
erally extending their application.' These experiments 
were continued to the year 1851, every series embra- 
cing a rotation of rye, potatoes, oats, and clover. The 
farmers were requested to try bone-dust, rape-cake, 
meal, guano, and farm-yard manure, each on a Saxon 
acre ( = 1-36 English acre) of ground compared with 
an unmanured plot of the same size, and to determine 
the respective crops by weight. 

Of all experiments of a similar nature which have 
been made in the course of several centuries, those 
which are expressly stated to have been undertaken 
'without a direct scientific object' are of the highest 
scientific importance, not only for their very compre- 
hensive character, but because they have resulted in 
fully establishing a number of facts which will for all 
time to come retain their validity as safe bases for 
scientific conclusions. Science owes the deepest grati- 
tude to the excellent propounder of these inquiries, and 
to the worthy men who so zealously performed their 
task ; the only thing to be regretted is, that the experi- 
ments upon unmanured plots were not carried out in 
all cases. 



186 



THE SYSTEM OF FARMYARD MANURING. 



It is evident that the action of farm-yard manure 
uj3on a field can be properly estimated only if it is 
known beforehand what amount of produce the field 
will give without any manure : and first of all we shall 
consider the crops produced on five fields in five dift'er- 
ent parts of Saxony, in the four-year rotation above 
mentioned. 





Unmanured. 




' 


Maueearast 


Kotitz 


Oberbobiitzsch 


ObcrschOna 


Crop. 


Cunnersdorf. 


mixture. 


white clover. 

lbs. 


red clover. 


grass. 




lbs. 


lbs. 


lbs. 


lbs. 


1851. 












Rye 












Grain. . . . 


1176 


2238 


1264 


1453 


708 


Straw . . , 


2951 


4582 


3013 


3015 


1524 


1852. 












Potatoes. . 


16667 


16896 


18577 


9751 


11095 


1853. 












Oats 












Grain. . . . 


2019 


1289 


1339 


1528 


1032 


Straw . . . 


2563 


1840 


1357 


1812 


1714 


1854. 












Clover-hay 


9U4 


6583 


1095 


911 


— 



These results lead to the following considerations. 

The term unmanured^ as applied to these fields, is 
meant to designate the condition in which they were 
left at the end of a rotation by a succession of crops. 

These fields had been manured at the beginning of 
the rotation ; and had they been manured afresh, they 
would have produced the same crops as before. In the 
crops yielded by them in the manured state, the con- 
stituents of the soil and those of the manure had a cer- 
tain definite share ; if the fields had not been manured, 
the crops would have been smaller. I*^ow if we at- 
tribute the increased produce during the course of the 
rotation to the supply of farm-yard manure, and suppose 
that the constituents of the farm-yard manure have 



THE SOIL AND TIIK PRODUCE. 1S7 

been again removed in the crops, \vliieli is not true in 
all cases, then the field, at the end of the rotation, is in 
the same state in which it was at the conunencement, 
before it had been mannred. Accordingly, we may 
assume, without great risk of error, that the produce of 
different crops, wliich a plot of ground Avill yield in a 
new rotation without manuring, will be in proportion 
to the store of nutritive substances, ready for assimila- 
tion, which it contains in its natural state. Hence from 
the unequal products yielded by the two fields in that 
state, we may, with an approximation to truth, infer 
certain inequalities in the amount of food or in the con- 
dition of the fields. 

Of course, inferences of this kind are admissible only 
within very narrow limits; for when we compare two 
fields wliich lie in the same or in different districts, we 
must remember that in each ca§e various factors operate 
upon the jjroduets, making these unequal, even though 
the nature of the soil be otherwise identical. 

If, for instance, two fields, both unmanured, are 
planted with one and the same cereal, it is by no means 
a matter of indifference, as regards the produce of corn 
and straw, what crop has preceded the cereal. If the 
last crop in the preceding rotation was clover on the 
one, oats on the other field, the results will vary, even 
though the condition of the soil in both was originally 
identical ; and the produce reaped, in that case, indi- 
cates merely the state into which the field has been 
brought by the preceding crop. 

In hilly districts, a northern or southern aspect 
makes a difference in the comparative character of two 
fields ; so too does the height above the sea, on which 
the quantity of the fall of rain depends. A fall of rain 
received at a more favourable time by one field than 
by another makes a difference in the amount of pi'O- 
duce, even though the condition of the soil be the same 
in both fields. 

Lastly, in judging, in the manner indicated, of the 
state and condition of a field, the weather during the 
preceding year must be taken into account. 



188 THE SYSTEM OF FAKM-VAKD MANURING. 

The crop produced by a field in a year is always the 
maximum crop which it can yield under the conditions 
given : under more favourable external circumstances, 
that is, with better weather, the field would have fur- 
nished a greater crop ; under more unfavourable circum- 
stances, a smaller, always corresponding to the condi- 
tion of the soil. 

By the production of larger crops, in consequence 
of favourable weather, the field loses a comparatively 
greater amount of nutritive substances, and the sub- 
sequent harvests show a decline;' just as, on the other 
hand, deficient crops will act upon the yield of subse- 
quent years, as a fallow year with half-manuring does, 
that is, the crops coming after bad years will turn out 
better, even in ordinary weather. 

The relative proportions of corn and straw, in a crop 
of cereals, are altered by a continuance of dry or wet 
weather. Permanent wet, combined with a high tem- 
perature, favours the development of leaves, stalks and 
roots ; and as the plant goes on growing, the materials 
intended for the production of seed are used for the 
formation of new shoots, and thus the seed crop is 
diminished. 

Continuous drought, before or during sprouting 
time, produces the opposite eft'ect ; the store of forma- 
tive matter accumulated in the roots is used in far 
greater proportion for the production of seed, and the 
relation of straw to corn is smaller than it would be in 
ordinary weather. 

When all these circumstances are taken into account, 
the consideration of the produce obtained from un- 
manured fields in the Saxon experiments will leave only 
a few general points for further investigation. 

The tabular statement of the result shows that each 
field has a power of production peculiar to itself, and 
that no two of them have produced the same amount 
of rye corn and straw, or potatoes, or oats and straw, or 
clover. 

If we compare the numberless manuring experi- 
ments of the last few years, in which the crops obtained 



THE PRODUCTIVE POWER OF LAND VARIES. 189 

from unraaniired plots were likewise taken into ac- 
count, we see that this is a general rule admitting of no 
exception : no two fields have exactly the same produc- 
tive power ; nay, tliere are not even two plots in tlie 
same field which are identical in this respect. We 
need only look at a turnip field to see at once that 
every turnip dilTers in size and Aveight from the one 
growing next to it. This fact is so universally known 
and admitted, that in all countries where the land is 
taxed, the amount of the impost is assessed according 
to the quality of the soil, in some countries in eight 
classes, in others in twelve or sixteen. 

Since, then, no two fields are alike in productive 
power, and every field must necessarily contain the con- 
ditions required for the production of the crops which 
it yields, it is clear that the conditions for the produc- 
tion of corn and straw, or of turnips and potatoes, or of 
clover or any other plant, are in no two fields alike : in 
one field the conditions for the production of straw pre- 
ponderate over those for the production of grain, 
another is better suited for the growth of clover, and 
so on. 

These conditions, according to their very nature, 
dificr in quantity and quality. By conditions which 
can be weighed and measured, we of course mean no 
other than nutritive substances. 

The crops reaped from a field afford no indication 
of the quantity of nutritive substances in the ground. 
Consequently, the fact that the field at Miiusegast gave 
twice as much corn and one-third more straw than the 
one at Cunnersdorf, cannot lead to the inference that 
the former was upon the whole richer in these proj)or- 
tions in the conditions for the production of corn and 
straw ; for we see that the Cunnersdorf field gave two 
years after, without manuring, one-half more oat-corn 
and straw than the field at Miiuscgast, and in the fourth 
year above 60 per cent, more clover. Kow some of the 
most important food elements of corn are as essential 
to clover as to the cereals ; and the food elements of 
oats are identical with those of rye. 



190 



THE SYSTEM OF FAKM-YAED LIANURING. 



A larger crop of any of the cultivated plants given 
by one field over another merely indicates that the 
roots in the one field in their way downwards, have 
found and absorbed in certain portions of the soil more 
particles of the wliole store of nutritive substances con- 
tained in it in an available state than the roots in the 
other field ; but not that the total sum was greater in 
the one than in the other: for the field apparently 
poorer might in reality have contained a much larger 
total amount of nutritive substances than the other, 
only not in a condition available to the roots 



RU 



:h returns are a sure sign that the nutritive sub- 



stances of the soil are in a condition available to the 
roots ; the jpermanence of high returns, and that alone, 
affords a safe criterion of the total store or quantity of 
nutritive substances in the ground. 

The high returns yielded by one field above another 
result from this, that the particles of the mineral con- 
stituents lie nearer together in the one field than in the 
other : they depend upon the closeness of the nutritive 
substances. The following table may make this point 
clearer : — 



Cunnersdorf, Miiusegast, Kotitz, Oberbobritzscb, Oberschona. 

Fiff. I. 1851. WiNTER-UTE. 




ILLUSTKATION OF INCREASE IN CROPS. 
Fig. II. 1852. Potatoes. 



191 



1 _H 



Fiff. III. 1853. Oats. 





-i 


h 


===: 




— = 




h 


i- 


_ 


- 



Fijr. IV. 1854. Clover, 







3< 


h 


^ 




k 




d 







In Fig. I., the pei'pendicular lines a h represent the 
produce of grain, a c that of straw ; in Fig. II., tlio 
lines d e the produce of potatoes ; in Fig. III., the lines 



192 THE SYSTEM OF FARM-YAED MANUEING 

/ (J tlie produce of oat-corn, the lines f h that of oat- 
straw ; in Fig. IV., the lines i k the produce of clover, 
on the unmanured plots of ground on which the experi- 
ments were made in Saxony. 

Now if we assume that the roots of the rye and of 
the other plants, on the several fields, were of the same 
length and condition, it is quite certain that the roots 
of the cereals on the field at Miiusegast found, in their 
way downwards, much more nutriuient than those in 
the Cunnersdorf field : the corn line is twice as high, 
and the straw-line one-third higher, in the former than 
in the latter. 

With an equal number of plants, and an equal 
length of root, certain nutritive substances required by 
corn were twice as close in the Miiusegast as in the 
Cunnersdorf field. The line in Fig. IV. representing 
the produce of clover is ten times as high for Cunners- 
dorf as for Oberbobritzsch, which means that the nutri- 
tive substances required by clover Avere ten times as far 
asunder in Oberbobritzsch as in Cunnersdorf. 

In comparing the produce of several fields, the close- 
ness of the nutritive substances in the soil is in inverse 
proportion to the height of the lines in the table indi- 
cating the amount of produce. 

The longer the lines, the closer are the nutritive 
substances in the various soils ; the shorter the lines, 
the more widely asunder do the substances lie. 

For instance, the lines indicating the produce of 
potatoes at Kotitz and Oberbobritzsch are as IS to 9 ; 
the potato crop at Kotitz was twice as high as that at 
Oberbobritzsch. Hence it follows that the distance 
between the nutritive substances was in inverse ratio, 
that is, as 9 to 18 ; in the field at Kotitz they were 
twice as close together as in the otlier. 

This mode of viewing the matter is calculated to 
lead, in many cases, to more definite ideas respecting 
the cause of the exliaustion of a field. 

The corn and potato crops, for instance, took away 
phosphoric acid and nitrogen from the arable surface 
soil at Miiusegast, and the barley plant next in rota- 



NEARNESS OF ELEMENTS OF FOOD IN SOILS. 193 

tion, w'liich likewise draws its nutriment from the sur- 
face soil, found in tlie third year nuicli less nutriment 
than the lye ])lant which had preceded it. 

The elevations of the lines a h (Fig. I.) and/*j7 (Fig. 
III.), taken inversely, show how much relatively greater 
has become the distance between the particles of the 
nutritive substances for the barley ])lant. The barley- 
corn requires for its tbrmation the same nutritive sub- 
stances as the rye-corn. Now, as the produce of the 
rye-corn was to that of the barley-corn in the pro])ortion 
of 22 : 12, this means, taken inversely, that the distance 
between the nutritive substances for the barley-corn had 
increased from 12 to 22. 

In the third year, the roots of the barley, for the 
same length, found scarcely half as much nutriment for 
grain as the rye had found. 

This exposition is not intended to supply a standard 
for measuring the distances between the available par- 
ticles of nutritive substances in the ground, but merely 
to define more accurately what is meant by the exhaus- 
tion of land. The farmer who has a clear view of the 
causes upon which depends the reduction of crops by 
continuous cultivation, will thereby the more easily find 
out and apply the means to make his field as productive 
as before, and, if possible, even to increase its fertility. 

Beside the general differences of all the crops in the 
Saxon experiments, we are further struck with the in- 
equality in the proportion of corn and straw. 

To 10 jmrts \)\ weight of corn, the yield of straw 
was respectively — at Cunnersdorf 25 parts by weight, 
at Kotitz 23, at Oberschona only 21, and at Miiusegast 
only 20. 

A more careful examination of the table shows that 
the difference is mainly in the produce of corn. 

The fields at 

Cunnersdorf. Kotitz. Oberbobritzsch. 

Yielded in straw 2951 lbs. 3018 lbs. 3015 lbs. 

that is, M'ithin a few pounds, the same quantity of 5^;'aw>, 
while the amount of corn was in 



194 THE SYSTEM OF FAKM-YARD MANURING. 

Cunnersdorf. Kotitz. Oberbobritzsch. 

11 : 12 : 14 

In investigating the reasons for this ineqnality in the 
prodnce of corn, we discover at the same time the causes 
of the diiference in the proportion between the corn and 
straw. 

It is necessary to remember that what is called straio 
(i. e. the leaves, stalks, and roots) is formed from the al- 
bumen of the cereal seeds, that is, from the constituent 
elements of the seeds ; and, further, that these parts of 
the plant are the organs for the reproduction of these 
same seed constituents. 

The production of the straw always precedes the 
formation of the grain ; and that portion of the seed 
elements which serves to form the organs of the plant 
cannot be used to make seed : or, the more seed-con- 
stituents are turned into straw-constituents within the 
appointed time of growth, the fewer will remain at the 
close of that period for the formation of seed (see p. 63). 

Before the period of flowering, all the seed-constitu- 
ents go to form straw ; after that period, a division takes 
place. 

Therefore, if all other conditions of soil and w^ eather 
are equally favourable, the quantity of straw will de- 
pend upon the amount of seed-constituents needed for 
the formation of straw. 

The quantity of corn depends upon the residue of 
seed-constituents in the whole plant, wdiich are no longer 
required for the multiplication and enlargement of 
leaves, stalks, and roots. 

Let K represent that portion of the corn constituents 
that may be formed into seed ; aK the other fraction of 
the same substances, which remain as constituents in 
the straw ; and '&t the other constituents comprised in 
the straw : so that 

K=(phosphoric acid, nitrogen, potaf3h, lime, magnesia, iron), 
aK=a fraction of K, 
S<=(silicic acid, potash, lime, magnesia, iron); 

then the nutritive substances which the plant has ab- 
sorbed from the soil, may be thus expressed : — 

(K + aKSO- 



CORN AND STKAW CONSTITTENTS IN SOILS. 195 

This expression, therefore, means that the roots of 
the cereal plant must have absorbed from the earthy 
particles in contact with them a certain proportion of 
nutritive substances for the i)rodnction of leaves, roots, 
and stalks, and after this an additional amount of sev- 
eral of the same constituents for the formation of grain. 
The total produce is, of course, dependent upon the sum 
of the K and &>£ constituents, which the soil is able to sup- 
ply to the plants during the natural period of growth. 

" The ratio between corn and straw results from a 
division of the K and St constituents in the plant itself, 
and depends upon the relative proportion of the K and 
St constituents in the soil, as also upon the action of 
external causes favouring the production of corn or 
straw. 

When the quantity of K constituents in tlie ground 
decreases, less grain will be produced ; but it is only in 
certain cases that this will exercise any influence upon 
the produce of straw\ 

AVhen the quantity of S^ constituents in a field is 
increased, the enhanced conditions for the formation of 
leaves, stalks, and roots, must injure the crop of grain, 
if the amount of «K required for the additional forma- 
tion of straw is taken from the store of K contained in 
the soil. 

If one of two fields is poorer in K but richer in S^ 
constituents than the other, the former may give the 
same, perhai)s even a larger, amount of straw, than the 
latter, but ns produce of corn will necessarily be less. 

A similar increase of straw, at the expense of grain, 
takes place when the state of the weather is more fa- 
vourable for the formation of leaves, stalks, and roots, 
than for grain. The period of growth is thus jjro- 
longed, and the plant then takes up more of the S^ con- 
stituents, which are usually in excess ; for the assimila- 
tion of these, a certain additional quantity of the K 
constituents is consumed, M'hich would otherwise have 
served to form seed. 

Let 8t represent the additional supply of S^ constitu- 
ents afibrded by the soil under these circumstances, and 



196 THE SYSTEM OF FARM- YARD MANURING. 

ak the additional portion of K converted into straw- 
constituents ; then the alteration in the produce may 
be expressed as follows : — 

Corn. StraTT. 

(K — ak) + (aK S< + ak st) ; 

that is, the produce of straw increases, while that of 
grain diminishes. It is also evident, that where the S^ 
constituents are in excess and the amount of K constitu- 
ents is increased, then if K is proportionately deficient 
there will be an increase in the produce of straw, and if 
K is proportionately increased there will be a larger 
produce both of corn and straw\ 

As the constituents of K, with the exception of nitro- 
gen and phosphoric acid, are also constituents of S^, this 
accession of ])roduce in the field under consideration 
will be also eff'ected either by a supply of phosphoric 
acid, or of nitrogen, or both together. 

If by this supply the closeness of the K particles in 
the ground, or of the phosphoric acid and ammonia par- 
ticles, is doubled, then under the most favourable cir- 
cumstances the harvest may be doubled by the supply 
of K. 

If, on the other hand, the soil is deficient in S^ con- 
stituents, any increase of nitrogen or phosphoric acid in 
the ground will fail to exercise the slightest influence 
upon the crop. 

It results from this, as a matter of course, that the 
absolute or relative amount of straw, given by a field in 
a crop of corn, wdl furnish no proof of the S^ constituents 
in the soil : since, though two fields may be equally }'ich 
in these constituents, the produce of straw de^Dends upon 
the quantity of K constituents in the ground : hence 
the field which is richer in K, will, under like circum- 
stances, give a larger crop of straw. 

The fact, therefore, that the fields at Cunnersdorf 
and 01)erbobritzsch yielded a like amount of straw, 
cannot lead to the inference that these fields contained 
an equal quantity of S^ constituents, since the corn 
crops show that the quantities of K were unequal. The 
harvests exhibited the following proportions : — 



RELATIVE PROPORTION OF CORN AND STRAW. 197 

In Ciinncrsdorf as (11) K : (20) aK St. 

" Kiititz as (l->) K : (8(i) aK St. 

" Obeiljobritzsch as (14) K : (30) aK S^. 

As befoi'e remarked, the constituents represented by 
the symbols K and Hi differ merely in this, that K com- 
prises nitrogen and phosphoric acid, while the other 
constituents of K arc common to both ; hence the dif- 
ference in the corn crops of these three fields results 
mainly from the fact, that the roots of the corn found 
in the soil at Kotitz ,-\ and at Oberbobritzsch ^^^ more 
phosphoric acid and nitrogen in an available condition 
than at Cunnersdorf. 

If the question is asked, how mucli phosphoric acid 
and nitrogen must be added to the field at Cunnersdorf 
in order to make the crop of corn equal to that of Ober- 
bobritzsch, it would be a mistake to suppose that an 
increase of /^ would be sufficient ; for the augmenta- 
tion of the ]U'oduce of corn is materially influenced by 
the S^ constituents, the quantity of which varies greatly 
in different soils and has not been ascertained. 

By the addition of nitrogen and phosphoric acid, a 
certain ([uantity of the accumulated S^ constituents are 
rendered effective or available, which before were not 
so ; but while the produce of straw increases, not y\, 
but less of nitrogen and phosphoric acid remain over for 
the formation of seed ; the exact quantity is limited by 
the total amount of transformed S^ constituents. 

The closeness of the S^ constituents in different soils 
may, however, be approximately ascertained from the 
relative proportion of corn and straw obtained from a 
plot manured with phosphoric acid and nitrogen, and 
from an unmanured ])lot respectively. 

If the unmanured plot yields corn and straw in the 
proportion of 1 : 2'5, and the manured plot gives a 
larger crop in which the corn is to the straw as 1 : 4 
(straw being in greater proportion), it is evident that 
the S^ constituents ])reponderate in the latter field ; and 
a much larger quantity of phosphoric acid and nitrogen 
would have to be supplied in order that the field, cor- 
respondently with its amount of S^ constituents, might 



198 



THE SYSTEM OF FAKM-YAKD MANURING. 



produce the same relative proportion of corn and straw 
as, for example, the land at Oberbobritzsch. 

It is a very essential part of the farmer's business to 
study the nature of his field, and to discover which of 
the nutritive substances, useful to plants, his land con- 
tains in preponderating quantity : for thus he will know 
how to make a right selection of such plants as require 
for their developement a superabundance of these con- 
stituents ; and he will obtain the greatest profit from his 
field, when he knows what nutritive substances he 
must supply in due proportion to those which are 
already in abundance. 

Two fields, in which the total amount of nutriment 
is unequal, but the relative distribution of the sub- 
stances is the same, will produce crops difiering in 
quantity, but agreeing in the relative proportion be- 
tween corn and straw. 

Such a relation, for example, exists between the 
field at Oberbobritzsch and the field at Mausegast. If 
the crop of corn and straw in the former is expressed by 
K + «K S^^, the crop in the latter = l-|-K + l-|aK St. 

The fields are evidently cultivated in both places 
with great care and skill, and the soil is so uniformly 
mixed, that when we know the corn and straw crop of 
the one, and the straw crop of the other, we can calcu- 
late the corn crop of the latter from the above formula. 

Potatoes., 1852. — In the subjoined table, the vertical 
lines show the potato crops from five different fields in 
the year 1852. 

1852. Potatoes. 
Cunnersdorf, Mausegast, Kotitz, Oberbobritzsch, Oberschona. 





-1 


e 


• 






-— 


e 


=1 


- 



A POTATO-CROP AND THE MINERALS IN THE SOIL. 199 

The potato plant draws its principal constituents 
from the arable surface soil, and from a somewhat 
deeper layer than the rye })lant ; and the crops reaped 
show the condition of the layers more accurately than 
could be ascertained by chemical analysis. 

In the fields at Miiusegast and Cunnersdorf the nu- 
tritive substances available for the potato plant were 
about equally close ; in Kotitz they were one-ninth 
closer to each other ; at Oberbobritzsch they were twice 
as far asunder ; while at Oberschona they were one-fifth 
closer than in Oberbobritzsch. 

The largest potato crop was obtained from the field at 
Kotitz. Potash (for the tubers) and lime (for the herb- 
aceous parts) are the predominant constituents of the 
potato plant : but a certain amount of nitrogen and 
phosphoric acid is as necessary for the developement of 
the potato as it is for cereals ; and the effective quan- 
tity of the transmuted potash and lime is essentially 
determined by the phosphoric acid and nitrogen ab- 
sorbed at the same time. Where one of the two latter 
elements which, as we have remarked, are equally con- 
stituents of cereals, is deficient in the soil, the potato 
crop will be proportionate to the available quantity of 
these two substances, and the greatest excess of potash 
or lime in the soil will have no influence whatever upon 
the amount of the produce. 

The arable surface soil of the field at Oberbobritzsch 
is much richer in phosphoric acid and nitrogen than 
that of the Kotitz field ; yet the potato crop yielded by 
the former was only half that given by the latter. 

Accordingly, nothing can be more certain than that 
the field at Oberbobritzsch contained much less potash 
or lime in an available state, than the Kotitz field ; and 
by manuring with lime alone, or with wood-ashes (pot- 
ash and lime), it might readily be ascertained in which 
of the two substances the ground was deficient. 

But from the inferior potato crop given by the field 
at Cunnersdorf, we cannot infer that it was poorer in 
potash or lime than the field at Kotitz ; the latter de- 
cidedly contained, as the preceding corn crop shows, 



200 



THE SYSTEM OF FAEM-TAKD MANUKING. 



somewhat more pliosphorie acid and nitrogen than the 
field at Ciinnersdorf : consequently, the larger potato 
crop at Kotitz may have been mainly owing to the 
greater quantity of these two elements contained in it. 
Even if tlie field at Cunnersdorf had been still richer in 
potash and lime than the Kotitz field, yet after all, 
nnder the given conditions, it would have produced a 
smaller crop of potatoes, 

Oats, 1853. — The oat plant derives part of its nutri- 
ment from the arable surface soil, but sends its roots, 
when the soil permits, nuicli deeper than the potato ; it 
possesses, so to speak, a higlier power of vegetation than 
the rye plant, and in the faculty of appropriating nutri- 
ment resembles weeds. 

1853. Oats. 
Cunnersdorf, Mausegast, Kotitz, Oberbobritzsch, Oberschona. 



M ^ g. 



The point which most strikes us in this table is the 
great inequality in the produce of two cereal plants 
grown successively on the same unmanured soil. 

The field at Cunnersdorf, which next to that at Ober- 
schona had given the lowest crop of rye-corn and straw, 
yielded in the third year the largest produce of oat-corn 
and straw. 

The difierence in the condition and closeness of the 
nutritive substances in the lower layers of these fields is 
undeniable. The field at Cunnersdorf was poorer iu 
the upper layers, but went on increasing downwards 
in the amount of substances nutritive to the corn plant ; 
the other fields decreased downwards. 

The returns of the field at Mausegast for the year 
1853 refer to barley and not to oats : hence they aflbrd no 
conclusion as to the condition of the deeper layers, from 



CLOVER CROPS AND THE MINERALS IN THE SOIL. 201 

which the oat plant derives its food : but they show the 
state into which the arable surface soil had been broni2;ht 
by the preceding corn crop. Owing to the abstraction 
of phosphoric acid, and j^erhaps of nitrogen, the yield 
of barley-corn was much less than might have been ex- 
pected from the soil, judging by the preceding rye crop ; 
and a small supply of superphosphate or guano would 
have greatly increased the produce of barley on this 
field. 

Cover, 1854. — Tlie clover crops in the fourth year 
afford an insight into the condition of the deepest layers 
from which plants draw their food. 

1854. Cloter. 
Cunnersdorf, Mausegast, Kotitz, Oberbobritzsch, Obcrschona. 




The produce of clover at Cunnersdorf was nearly 
twice as large as at Mausegast, and ten times greater 
than at Oberbobritzsch ; and it is beyond doubt, that 
these unequal crops must have corres])onded to unequal 
amounts in the soil of substances nutritive to the clover 
plant. 

The substances required by the clover plant, in re- 
spect of quantity and relative pro])ortion, are very 
nearly the same as for the potato plant (leaves, stalks, 



202 THE SYSTEM OF FAKM-TAED MANUKING. 

and tubers included) : and if clover still yields good 
crops upon a soil wherein potatoes thrive but imper- 
fectly, this is chiefly owing to the wider root-ramiflca- 
tion of the clover plant. There are scarcely any two 
other plants which so clearly indicate the layers of the 
soil assigned to them by nature, for the absorption of 
their nutriment. 

If potatoes are planted in trenches two feet deep, 
and if these are filled up in proportion as the plant 
grows, so that at last the earth in the trench is on the 
same level with the arable surface, it is always found 
that the tubers are formed only in the topmost layer, 
none at a greater depth, and not more in number than 
if the seed-potatoes had been planted only 1|- or 2 
inches deep in the arable surface soil : and on gathering 
the crop it is observed that the roots below the arable 
surface have died away. 

"With clover, the case is reversed ; and although the 
arable surface soil at Kotitz, for example, is decidedly 
richer in substances nutritive for clover than that in 
Cunnersdorf (yielding a potato crop higher by one- 
eighth), this had no effect upon the clover, which 
receives its principal nutriment from the deepest layers 
of the soil. 

We now proceed to an analysis of the returns which 
were obtained, in the Saxon experiments, by employing 
farm-yard manure upon the plots of the same fields, 
the crops of which in their unmanured state we have 
just been considering. 



THE PRODUCE NOT IN PKOPOKTION TO THE MANURK, 203 



Produce^ per Saxon acre, of the fields dressed with farm-yard 

manure. 





Cunncrsdorf. 


M;iusegast. 


Kutitz. 


Obcrbobritzsch 


Oberschona. 




cwt. 


cwt. 


cwt. 


cwt. 


cwt. 


Farm-yard [ 
manure. . . J 


180 


194 


229 


314 


897 


1851. 


lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


Rye corn .... 


1513 


2583 


1616 


1905 


1875 


" straw .... 


4696 


5318 


4019 


3928 


8818 


1852. 












Potatoes 


17946 


20258 


20678 


11936 


16727 


1853. 












Oat corn 


2278 


1649 


1880 


1685 


1253 


" straw .... 


2992 


2475 


1742 


1909 


2576 


1854. 












Clover-hay. . . . 


9509 


7198 


1232 


2735 


0* 



Increase ty farm-yard manure over unmanured plots. (See p. 186.) 





Cunoersdorf. 


Hausegast. 


Kotitz. 


Obetbobiitzacb. 


Oberschona. 


1851. 

Rye corn .... 

" straw. . . . 


lbs. 

337 
1745 


lbs. 

345 

736 


lbs. 

352 
1006 


lbs. 

452 

915 


lbs. 

1167 
229 


1852. 
Potatoes 


1279 


3362 


2101 


2185 


5632 


1853. 

Oat corn 

" straw. . . . 


369 
429 


360 
635 


541 

385 


157 
97 


171 
862 


1854. 
Clover-hay . . . 


365 


1615 


137 


1824 


* 



Here, again, what strikes lis first is that the returns 
from all the fields were diftercnt from one another, and 
that apparently they did not bear the most remote rela- 
tion to the quantity of manure applied. 

Nothing can be more certain than the fact that a 
field, exhausted by cultivation, will yield larger returns 
if dressed with farm-yard manure than if unmanured : 

* The clover crop failed from excessive wet. 



204 



THE SYSTEM OF FAKM-YAED MANTJEING. 



now, taking tlie increase to be caused hj manure, it is 
natural to suppose that the same quantity of manure 
would produce the same increase upon ditferent iields. 
The following table, however, shows that the same 
quantity of manure, upon the Saxon Helds, produced 
results which differed very considerably. 

One hundred ciDt. of farm-yard manure gave increased froduce. 





Cunnersdorf. 


Mausegast. 


Kolitz. 


Oberbobritzsch. 


Oberschona. 




lbs. 


lbs. 


lbs. 


lbs. 


lbs. 


1851-53. 












Winter rye & ) 
oats ) 


1539 


lOTO 


988 


515 


601 


1852. 












Potatoes 


720 


1723 


917 


690 


628 


185i. 












Clover 


203 


832 


60 


628 


— 



No one looking at these numbers could divine that 
they were intended to represent the effects produced 
upon five different fields by an equal quantity of the 
same manure, and that too the universal manuring 
agent. 

Neither in the crop of rye-corn and straw, nor in 
that of potatoes, oats, and clover, is there the slightest 
resemblance or correspondence ; still less is it possible 
to discover what amount of manure has been instru- 
mental in producing the increased crops. 

The same quantity of farm-yard manure gave, in the 
years 1851 and 1853, at Mausegast double, at Cunners- 
dorf three times, the increase of cereal crops, corn and 
straw together, that was obtained at Oberbobritzsch : 
the increase of tlie potato crop at Mausegast was twice 
as large as in Kotitz ; of clover, four "times more in 
Mausegast than in Cunnersdorf; and in Oberbobritzsch, 
ten times as much as in Kotitz. 

The enormous quantity of farm-yard manure put 
upon the field at Oberschona failed to produce anything 
like the crop obtained from the unmanured field at 
Mausegast. 



CROPS FKOM FA KM- YARD MANURE VARY. 



205 



The composition of farm-yard manure, as we know 
from numerous analyses, is on the whole so mucli alike 
iu all [)laces, that wo may suppose without great risk of 
error that in 100 cwt. of farm-yard manure every field 
receives the same nutritive substances and in the same 
quantities. 

Tiic constituents of farm-yard manure act every- 
where in the same way u])on the soil or the earthy par- 
ticles. Kow this ajiparcntly involves an irreconcilable 
contradiction with the fact that the increase obtained by 
it is nevertheless everywhere different, and that the 
dung-constituents supplied will, on one field, set in 
motion and render available to the cereal or potato 
plants growing on it, twice or three times as many ele- 
ments of food as on another field. 

This fact does not refer to the Saxon fields alone, 
but applies generally. Nowhere, in no country, do the 
crops obtained by farm-yard manuring on diflerent 
fields ever coiTcspond, as the following table of the 
average produce of divers crops in difl:erent provinces 
of the kingdom of Bavaria will show. 

Aterage Crops i\ Bataria. 

{Seuff'ei'fs Statistics.) 

One day's work yields average produce in bushels.* 



1 Wheat. 


Eye. 


Spelt. 


Barley. 


Oats. 


Upper iJavaria ... 


1-70 
2-50 
1-45 
1-20 
1-6.5 
1-70 
1-80 
2-70 


1-80 
1-80 
1-40 
1-30 
1-40 
1-75 
2-00 
2-60 


3-40 

3-40 

2-70 

2-20 

3-50 

2 50 

5-0 

4-80 


1-90 
1-90 
1-75 
1-50 
1-65 
2-00 
2-30 
3-75 


2-31 


Lower B;ivaria 

Fppcr Palatinate and Ratisbon . . 
Upper Fraiiconia 


2-31 
1 85 
1-75 


Middle Fraiiconia 


2-25 


Lower Franconia and Ashaffenburg 

Suabia and Xeuburg 

Palatinate 


2-75 
3-50 
3-90 







* 1 Hectolitre weighs on an averatje 

Zollvercin weight. 

■Wheat 146 lbs. 

Barley 128 " 

Rye 140 " 

O.its 88 " 

Spelt (in the husk) 79 " 



1 Bavarian bnshel. 
ZoUvcrein weight. 
330— ,345 lbs. 
200—300 " 
318—323 " 
200—300 " 
174—220 " 



According to this scale, the weight of a Prussian bushel of wheat is 



206 THE SYSTEM OF FAKM-YARD MANURING. 

The crops produced by farm-yard manuring differ 
not only in every country, but even in every locality ; 
and, strictly speaking, every Held dressed with farm- 
yard manure yields an average produce of its own. 

The action of farm-yard manure upon the increase 
of produce is intimately connected with the condition 
and composition of the soil ; it varies, therefore, in dif- 
ferent fields, simply because the composition of the soil 
varies. 

To understand the action of farm-yard manure, it is 
necessary to remember that the exhaustion of a field 
arises from the loss of a certain amount of nutritive con- 
stituents, at the end of a rotation, inflicted upon the 
soil by preceding crops, which of course leave less avail- 
able food in the soil for the following crops. 

However, the loss of each individual constituent has 
not the same effect upon the exhaustion of the soil. 

The loss of lime which a calcareous soil suffers by a 
cereal or by clover, matters little to the growth of a 
succeeding plant that requires large quantities of lime 
to thrive well. The same applies equally to the loss of 
potash, magnesia, iron, phosphoric acid, nitrogen, on 
fields severally abounding in potash, magnesia, iron, 
phosphoric acid, or ammonia. Where a soil is abun- 
dantly provided with one of the mineral constituents, the 
amount of that constituent removed by the crops is so 
small a fraction of the whole mass, that the effect of the 
diminished store is not appreciable from one rotation to 
another. 

But practical experience shows that the crops do de- 
crease from one rotation to another, and that the land 
requires a fresh supply of certain ingredients by manur- 
ing, if it is again to produce as large harvests as before. 

Now, as a supply of lime cannot be expected to re- 
store the fertility of an exhausted field where lime con- 
stitutes the principal bulk of the soil, just as little as a 
supply of potash or phosphoric acid to a field abounding 
in potash or phosphoric acid, it is easy to understand 

83 lbs., and that of the English quarter 425 lbs., 100 lbs. (Zollv. weight 
= 110-2 lbs. avoir.). 



CROPS, now GOVERNED. 207 

tliat where the productive power of an exhausted field 
is restored, the fertilising etiect is to be attributed sim- 
ply to the manure returning to the Held those elements 
of food which the soil originally contained in the least 
proportion, and of which it has accordingly lost, by the 
preceding crops, comparatively the largest fraction. 

Every lield contains a maximum of one or several, 
and a minhmon of one or several, other nutritive sub- 
stances. It is by the miniimim that the crops are gov- 
erned, be it lime, potash, nitrogen, phosj^horic acid, 
magnesia, or any other mineral constituent ; it regu- 
lates and determines the amount or continuance of the 
crops. 

Where lime or magnesia, for instance, is the mini- 
mum constituent, the produce of corn and straw, tur- 
nips, potatoes, or clover, will not be increased by a sup- 
ply of even a hundred times the actual store of potash, 
phosphoric acid, silicic acid, &c., in the ground. But 
a simple dressing with lime will increase the crops on 
a field of the kind, and a much larger produce of cere- 
als, turnips, and clover will be obtained by the use of 
this agent (just as is the case by the application of 
wood-ashes on a field deficient in potash) than by the 
most liberal use of farm-yard manure. 

This sutficiently explains the dissimilar action upon 
different fields of so composite a manm-e as farm-yard 
dung. 

Only those ingredients of farm-yard manure which 
serve to supply an existing deficiency of one or two of 
the mineral constituents in the soil act favourably in 
restoring the original fertility to a field exhausted by 
cultivation ; all the other ingredients of the manure, 
which the field contains in abundance, are completely 
without effect. 

A field rich in straw-constituents cannot be made 
more productive by maimring with straw-constituents 
in the dung, whereas these constituents will prove most 
efficacious on fields deficient in them. 

If two fields have the same abundance of straw-con- 
stituents, but are not equally rich in corn constituents, 



208 THE SYSTEM OF FAKM-TAKD MANUKING. 

the same supply of farm-yard manm-e will not produce, 
by any means, equal crops of corn, because these must 
bear a relation to the corn-constituents supplied in the 
manure. Of these, both lields received the same 
amount in the same quantity of manure ; but as the 
one iield, of itself, was richer in corn-constituents than 
the other, the poorer of the two must receive much 
more manure to make it produce as large crops as the 
other. 

A comparatively small quantity of superphosphate 
will, on a field of the kind, serve to increase the produce 
to a much greater extent, than the most liberal use of 
farm-yard manure. 

Upon a field deficient in potash farm-yard manure 
acts by the potash contained in it ; upon a soil poor in 
magnesia or lime, by its magnesia or lime ; upon one 
poor in silicic acid, by the straw in it ; upon land poor 
in chloride or iron, by the chloride of sodium, chloride 
of potassium, or iron contained therein. 

This fact accounts for the high favour in which 
farm-yard manure is held by practical farmers. As the 
dung of the farm-yard contains, under all circumstances, 
a certain quantity of each of the mineral constituents 
withdrawn from the soil by the crops grown on it, its 
action is universally beneficial. It never fails to pro-' 
duce the desired effect, and thus spares the practical 
man the trouble of devising more suitable and equally 
efficacious means for keeping up the fertility of his 
fields, with a less profuse expenditure of money and 
labour, or of raising his land, without additional outlay, 
to the highest attainable degree of fertility compatible 
with its composition. 

It is well-known in practice, that the produce of 
many fields may be increased by manuring with guano, 
bone-dust, rape-cake, and other substances containing 
only certain constituents of farm-yard manure ; and 
their operation is explained, in effect, by the doctrine 
of 7ninimum, which I have just laid down. 

But as the practical farmer is not acquainted with 
the law which regulates the operation of these manur- 



ERKOR IN USING TOO ML^CH MANITKE. 209 

ing agents as affecting the increase of produce, he can, 
of course, have no correct notion of their rational, -which 
means their truly economical, use ; he puts on his hmcl 
too nnicli, or loo httle, or chooses the MTong aiicnt. 
The error of employing too little manure needs no ex- 
planation ; lor every one knows that the right piopor- 
tion of manure Avill, -with exactly the same labour and 
at a trifling additional outlay, ensure the maximum 
produce of which the land is capable. 

The error of using too much manure arises from the 
mistaken notion that the action of manures is propor- 
tionate to the quantities in which they are applied ; 
this is true up to a certain limit, but beyond this all the 
manure applied is sim[)ly thrown away, as far as any 
fertilising action is concerned. 

A manuring experiment made by Mr. J. Kussell, 
of Craigie House (* Journal of the Koyal Agr. Soc. of 
England,' vol. xxii. p. 86), may, perhaps, serve to illus- 
trate our meaning. In this experiment a field was 
divided into a number of plots of three rows each, all 
planted with turnips, some of the plots being left un- 
manured, the remainder dressed severally with difierent 
manuring agents, among others with superphosphate 
(bone-ash dissolved in sulphuric acid). The produce, 
calculated per acre, was as follows : — 

Produce jjer acre. 

No. of plots. Cwt. 

I. Unmanurcd 340 turnips (Swedes). 

II. " 320 

V. Manured with 5 cwt. of superphosphate. . 535 " 

VI. " 5 " " .. 497 " 

VII. " 3 " " .. 480 " 

VIII. " 7 " " .. 499 " 

IX. " 10 " " .. 490 " 

As shown by the difference of 20 cwt. in the produce 
of the unmanurcd plots, the condition of the soil and 
the store of mineral constituents differed, to some ex- 
tent, in different parts of the field. Other experiments, 
which we cannot describe more particularly, showed 
that the soil was poorer in the centre of the licld than 
on the sides. 



210 THE SYSTEM OF FAKM-YAKD MANURING. 

The one great fact most clearly proved by the above 
table of produce is, that 3 cwt. of superphosphate gave 
nearly the same crop of turnips as 5 cwl. ; and that a 
further increase of the manm'e to 10 cwt. produced no 
additional increase of the crop. 

No steps were taken, in these experiments, to ascer- 
tain which of the constituents of superphosphate of lime 
had the principal share in increasing the produce of the 
field. Magnesia and lime, as well as sulphuric and 
phosphoric acid, are equally indispensable elements of 
food for the turnip plant ; and I have observed that by 
manuring with gypsum and a little common salt or with 
phosphate of magnesia, a field will be made to give 
more abundant crops than, by employing superphos- 
phate of lime, although the latter unquestionably proves 
the most eftective manure for most fields. 

To apprehend these facts correctly, we must remem- 
ber that the law of the oninimum does not apply to one 
constituent alone, but to all. Where, in any given case, 
the crops of any plant are limited by a minimum of 
phosphoric acid in the field, these crops will increase 
by augmenting the quantity of phosphoric acid up to 
the point at which the additional phosphoric acid bears 
a proper proportion to the next minimum constituent 
in the soil. 

If the additional phosphoric acid exceeds the corre- 
sponding quantity, for instance, of potash or ammonia 
in the soil, the excess will prove of no effect. Before 
the supply of phosphoric acid the available quantity of 
potash or ammonia was a little larger than the amount 
of phosphoric acid in the soil, and the excess of the 
alkalies was inefi'ective until the phosphoric acid was 
supplied ; similarly the excess of phosphoric acid must 
remain just as inoperative, as previously the excess of 
potash. 

Whilst the produce before was proportionate to the 
minimum of phosphoric acid, it is now in proportion to 
the minimum of potash or ammonia, or both alkalies. 
A few experiments made on Mr. Russell's field might 
have settled the question. Had potash or ammonia 



THE LAW OF MINIMUM. 211 

been the minimum, after manm-ing with superphos- 
phate, a suitable supply of potash or ammonia, or both, 
would have increased the produce. In this same series 
of experiments, cwt. of guano, corresponding to 2 cwt. 
of superphosphate, gave a crop of 630 cwt. of turnips, 
or 130 cwt. more than the superphosphate ; but it is 
left in doubt whether this increase was attributable to 
the potash or the ammonia in the guano. 

To return to our Saxon experiments. If we look at 
the different quantities of dung applied severally on 
the five fields, we are naturally led to inquirq the 
reason of this diversity. 

The most feasible answer, perhaps, is, that the far- 
mer gives as much manure as he has at his disposal, or 
that he regulates the quantity according to certain 
facts. If he has found by experience that a certain 
quantity of farm-yard manure will restore his land to 
its original fertility, and that more copious manuring 
will fail to give larger crops, in proportion to the addi- 
tional supply, or to the cost incurred in collecting the 
manure, he will stop at the smaller quantity. 

Hence it cannot be regarded as a mere accident that 
the farmer at Cunnersdorf contented himself with 180 
cwt. of farm-3'ard manure, while the farmer at Ober- 
bobritzsch laid 314 cwt. upon his field. 

But if the quantity of manure to be applied is not 
dependent upon chance or caprice, but is regulated by 
the object in view, it is manifest that the proceedings 
of the farmer are governed by a law of nature unknown 
to him, except by its effects. 

It is in the composition and condition of the soil 
that we must seek the law which regulates the quantity 
of farm-yard manure required, at tlie outset of a fresh 
rotation, to restore a field to its former fertility ; and it 
is not difficult to see tliat this quantity must always be 
proportionate to the eftective dung-constituents already 
present in the soil ; a field largely abounding in them 
takes less manure than a poor field to give tlie same 
increased produce. 

Now, as fann-yard manure owes its most active 



212 THE SYSTEM OF FAEM-YAED MANUKING. 

constituents to clover, turnips, and the grasses, tlie in- 
ference is pretty clear that the quantity of this manure 
required on a held is in an inverse ratio to the produce 
of clover, turnips, or grass, -which the field can give 
whin unuianured. 

The Saxon experiments show that this inference 
cannot be far from the truth, in one respect at least ; 
for on comparing the produce of clover given by the 
unmanured plots with the quantity of farm-yard 
manure applied, we find : — 

Clover crops hi 1854. 

Cur.nersdorf. Mfiusegast. KiUitz. Oberbobritzsch. Oberschdna. 
Pounds.. 9144 5583 1095 911 — 

Quantity of manure applied in 1851. 
Cwt 180 194 229 314 89Y 

The field at Cunnersdorf which contained the largest 
store of dung-constituents received the smallest ; the 
field at Oberbobritzsch which gave the smallest crop 
of clover, the largest quantity of farm-yard manure. 

The crop of clover, however, is not the only factor 
to determine the amount of farm-yard dung required 
for manuring ; for one of the clover-constituents, silicic 
acid, which is indispensable to the cereal plants, is 
present only in trifling proportion, and hence the quan- 
tity of farm-yard manure (straw-manure) must bear a 
definite ratio to the quantity of straw-constituents 
already present in the ground. 

If, in the Saxon experiments, we compare the in- 
creased produce of corn and straw obtained from the 
fields manured with farm-yard dung, we find : — 

Increase of p)i'od\ice by farm-yard manuring, per acre. 

Cunnersdorf. Kolitz. Oberbobritzsch. 

Quantity of farm-yard manure 180 cwt. 229 cwt. 314 cwt. 

Corn 347 lbs. S52 lbs. 452 lbs. 

Straw".'!!"..'..'.! 1743 " 1006 " 914 " 

The field in Cunnersdorf, manifestly the richest in 
substances nutritive for straw, gave the largest straw- 



RATIONAL SYSTEM OF FARMING. 213 

crop, although it had received the smallest quantity of 
farm-yard mamire. In the increased produce, corn was 
to straw as 1 : 5, clearly showini;' that sparing applica- 
tion of straw manure was the proper course to pursue 
here. This fact readily explains also why the held at 
Oherbobritzsch, comparatively poorer in straw-constitu- 
ents, required 85 cwt. of farm-yard manure more than 
the Kotitz field, to enable it to maintain, in its in- 
creased produce, the same proportion of corn and straw 
(1 : 2) as in the crop from the unmanured plot. 

These considerations might, perhaps, lead the prac- 
tical farmer to the conviction that he is, after all, not 
much of a free agent in the cultivation of his fields, and 
that the ' facts and circumstances ' which guide him in 
his proceedings are simply laws of nature, of whose 
existence he has scarcely any conception. In truth, it 
may be said that the agriculturist is a free agent only 
in his wrong-doings. If he acts in accordance with his 
own interest, he must allow himself to be guided, even 
though unconsciously, by the condition of his land ; and 
the only matter for wonder is, how far the man of ' ex- 
perience ' has succeeded in this way. 

A system of farming, to be called truly rational, 
must be exactly suited to the nature and condition of 
the soil ; for it is only when the rotation of crops or the 
mode of manuring is conformable to the composition of 
the soil, that the farmer has a sure prospect of realising 
the highest possible returns from his labour or from the 
capital invested. 

Now considering, for instance, the great difference 
in the condition of the soil at Cunnersdorf and Oher- 
bobritzsch, it is self-evident that the same rotation of 
crops which suits the one field, will not answer equally 
well for the other. 

If farmers would only make up their minds to ac- 
quire by experiments on a small scale,* an accurate 
knowlediye of the productive power of their land for 
certain kinds or classes of plants, a few more experi- 

* In a field of pretty uniform composition, experiments of this kind 
may be made with flower pots sunk in the earth. 



214 THE SYSTEM OF FAEM-YAED MANUEING. 

ments would readily enable them to discover what 
nutritive substances their land contains in minimum 
proportion, and what manuring agents ought to be ap- 
plied to ensure the production of a maximum crop. 

In matters of this kind the farmer must j^ursue his 
own course, and the proper course is the one that will 
most fully secure the object he has in view ; he must 
not put the least faith in the assertion of any foolish 
chemist, who wants to prove to him analytically that 
his field contains an inexhaustible store of this or that 
nutritive substance. For the fertility of a field is not 
proportionate to the quantity of one or several food 
elements analytically shown to exist in it, but to that 
fraction of the total nutritive substances which the field 
is able to give ujj to the plants ; and the only means of 
determining that fraction is by the plant itself. The 
most that chemical analysis can do is to supply a few 
data for comparing the condition of two fields. The 
experiments made by the beet-root growers on the ex- 
tensive tract of land in Russia, known as the Tscherno- 
sejn or ' Black soil,' whose fertility for corn plants is 
proverbial, show that this earth, though analytically 
proved to contain upon the whole, to the depth of 
twenty inches, 700 to 1000 times the quantity of potash 
required for a full beet-root crop, is, after three or four 
years' cultivation, so exhausted, that without manuring 
it will no longer yield a remunerative crop of beetroot.* 

In the produce of cereals there is only one proper 
proportion between grain and straw ; but the unfavour- 

* With regard to the general opinion about the abundance and inex- 
haustibihty of potash in land, the following announcement, in the ' Badische 
Centralblatt fih- Staats und Gemeinde-Interessen,' May 1861, is not without 
interest. ' In the District of Brettcn. — The contracts which usually take 
place in the early part of the year for the cultivation of beetroot, are now 
fully open for competition in this district, and for good articles 30 francs 
the cwt. are offered this year, whereas last year only 26 francs were paid. 
Notwithstanding this rise of prices, and the premiums offered for superior 
roots, not many transactions have been concluded. The reason of this is 
quite intelligible, for the very injurious effects resulting to land on which 
this product has been cultivated, are too well known.' The effects must 
have reference to fields which had been adequately manured, for otherwise 
no profitable returns can be expected. 



PEKMliABlUTY OF SOILS TO MANURES. 215 

able proportious are many. It is clear that the mass 
and extent of the organs for the formation of grain (in 
other words, the bulk of the straw) must bear a definite 
relation to the product, that is, to the quantity of grain 
produced : any excess or deficiency in the amount of 
straw must always act injuriously upon the grain crop. 

When it is known that, on a given field, one i)art 
by weight of corn to two parts by weight of straw is 
the most favourable proportion for the production of 
grain, then, according to theory, the manuring of the 
field should not be such as to cause any marked altera- 
tion of this relative proportion in the increased prod- 
uce ; that is to say, the several manuring substances 
should be selected and laid upon the field in such quan- 
tity and relative proportion, that the composition of 
the soil may remain the same as it was before. 

It is well known that certain manuring substances are 
especially favourable to the formation of the herbaceous 
parts of plants, others to that of seed. Phosphates, as a 
general rule, increase the grain crop : whilst of gypsum 
it is well known that where that substance eti'ects an 
increase in the produce of clover-hay, this increase is 
always attended with a marked diminution in the prod- 
uce of seed. The cultivation of potatoes or Jerusalem 
artichokes tends to reduce the excessive accumulation 
in the arable surface soil, of substances which j)romote 
the formation of the herbaceous parts of plants. 
Theoretically, therefore, it is not impossible to main- 
tain a certain uniformity of composition in the soil of a 
field ; but this cannot be efiected by carrying on the 
husbandry of an estate by the system of farm-yard 
manuring. It will hereafter be shown that by the con- 
tinuous and exclusive use of farm-yard manure, the 
composition of the soil is found changed after each 
rotation. 

The last point which claims our attention, in refer- 
ence to the Saxon experiments, is the diflerence in the 
permeability of the soil to the dung-constituents in the 
difierent localities. The depth to which the alkalies, 
the ammonia, and the soluble phosphates penetrate, 



216 THE SYSTEM OF FARM- YARD MANTJEING. 

depends of course upon the absorptive power of the 
soil ; now, assuming, for the sake of ilhistration, the soil 
of a field to be divided from the top downwards into 
distinct layers, which are not of course sharply sepa- 
rated from one anotlier, we find that in some localities 
the dung-constituents stop in the upper layers, whilst 
in others they penetrate to the deeper layers of the 
ground. Thus, for instance, in the Cunnersdorf field 
the clover crop had derived no benefit from the farm- 
yard manure, being about only 4 per cent, larger than 
the produce given by the unmanured plot; whereas 
at Miiusegast the manuring caused an increase of 30 
per cent., and at Oberbobritzsch of 200 per cent. This 
result shows that certain mineral constituents, indispen- 
sable for clover, penetrated much deeper into the 
ground at Miiusegast and Oberbobritzsch than at Cun- 
nersdorf and Kotitz ; or, what comes to the same, that, 
in the two latter places, they were, on their way down- 
wards, retained by the upper layer of the soiL On 
comparing the crops given by the unmanured plot at 
Cunnersdorf with those obtained from the unmanured 
plots in the other localities, we see that the Cunners- 
dorf field contained nearly as large a store of straw 
constituents as tlie fields at Kotitz and Oberbobritzsch, 
while it was decidedly poorer in the principal grain 
constituents, namely, in phosphoric acid and, perhaps, 
also in nitrogen. Hence, with an equal supply of 
phosphates and ammonia on the three fields, the top- 
most layer of the ground at Cunnersdorf, being poorer 
in these constituents, would retain a great deal more 
of them than that of the other two fields. 

The increase in the potato crop and in the produce 
of oat-grain and straw, on the Cunnersdorf field, clearly 
indicates that certain dung-constituents made their way 
to that layer of the soil from which the roots of the oat- 
plant priiici])ally derive their food, which layer, being 
richer in corn and straw constituents than the arable 
surface soil, permitted a small proportion of nutritive 
substances to pass through it and thus reach the clover. 

If we compare with this the field at Kotitz, and look 



COMPAEISON OF RESULTS IN AGEICULTUEE. 217 

at its extraordinarily scanty crop of oat-grain and straw, 
we see at once that in the latter field tlie deeper layers 
of the soil were much poorer in corn and straw con- 
stituents, but that the topmost layer was much richer 
in corn constituents than the land at Cunnersdorf. 

Although the Kcititz field received above 25 per 
cent, more farm-yard manure than the Cunnersdorf 
field, yet only a very insignificant portion of that 
manure found its way down to the clover, as the layer 
above had retained the substances nutritive to clover, 
and these had principally served to benefit the oat- 
plant. The increase in the produce of oat-grain at 
Kotitz was more than double that obtained from the 
Cunnersdorf field. At Miiusegast the relations were 
similar ; from the uncommon abundance of corn and 
straw constituents in the arable surface soil, the absorp- 
tive or retentive power of the latter for the dung-con- 
stituents in solution was comparatively less, and a con- 
siderable proportion of these substances was thus per- 
mitted to reach the deepest layers. The uniform rise 
of the successive crops obtained from the manured field 
at Oberbobritzsch evidently shows a very uniform dis- 
tribution of active dung-constituents, such as might be 
expected in a soil which, though not exactly sandy, yet 
contained a larger proportion of sand than any of the 
other experimental fields. 

It is easy to see, that by knowing the absorptive 
power of the arable soil in these several fields, the 
farmer is enabled to determine beforehand to what 
depth the nutritive substances supplied in the manure 
will penetrate into the ground ; and it follows, as a 
matter of course, that he is able to apply with greater 
efiect the mechanical means at his disposal for promot- 
ing the distribution of these elements in the soil, in the 
right places and in the proper manner. 

It would answer no good purpose to expatiate still 
further on this point ; my object has been to direct the 
attention of the farmer to the different facts or phenom- 
ena which are presented by his land during the process 
of cultivation ; because a closer observation of each 

10 



218 THE SYSTEM OF FAEM-YAKD MANURING. 

phenomenon will lead him to reflect npon the cause of 
it. This is the way to obtain an accurate knowledge of 
the state and condition of the soil. 

Observation and reflection are the fundamental con- 
ditions of all progress in natural science ; and agricul- 
ture presents, in this respect, ample room for discov- 
eries. What must be the feelings of happiness and 
contentment of the man who, by skilfully turning to 
proper account his intimate knowledge of the peculiari- 
ties of his land, has succeeded, without increased appli- 
cation of labour or capital, in gaining from it a perma- 
nent increase of produce ? For such a result is not 
only a personal advantage to himself, but a most im- 
portant benefit conferred upon all mankind. 

How paltry and insignificant do all our discoveries 
and inventions appear, com])ared to what is in the 
power of the agricultiirist to achieve! 

All our advances in arts and sciences are of no 
avail in increasing the conditions of human existence ; 
and though a small fraction of society may by their 
means be gainers in material and intellectual enjoyment, 
the load of misery weighing upon the great mass of the 
people remains the same. A hungry man cares not for 
preaching, and a child that is to learn anything at 
school must not be sent there with an empty stomach. 

Every step in advance, however, made by agricul- 
ture serves to alleviate the sufterings and troubles of 
mankind, and to make the human mind susceptible and 
capable of appreciating the good and the beautiful 
that art and science present to us. Improvements in 
agriculture constitute the only solid foundation for fur- 
ther progress in all other branches of knowledge. 

We now proceed to consider the changes brought 
about in the composition of the soil of a given field by 
cultivation by the system of farm-yard manuring. The 
cause to which the restoration of the power of produc- 
tion in the soil by farm-yard manure is attributable, is 
the same in the case of all soils, without exception, 
however v/idely the rotations may diff'er, or whatever 
be the nature of the crops cultivated upon them. 



. MINEKAL MATTERS RESTORED BY MANURE. ^19 

Bj the cultivation of cereals, and the removal of the 
corn-crops, the arable surface soil loses a certain por- 
tion of corn-constituents, which must be restored to it 
by fiirm-yard manure, if the future crops are to be kept 
up to the mark of the preceding ones. 

Tliis restoration is effected by the cultivation of fod- 
der-plants, such as turnips, clover, grass, &c., on which 
the cattle on the farm are fed, and the constituents of 
which are drawn, in large proportion, from the deeper 
laj-ers of the ground, where the roots of the cereals 
cannot penetrate. 

These fodder plants are consumed either on the field 
itself, as turni])s in England, or in the stalls. A frac- 
tion of the nutritive substances contained in these 
plants remains in the body of the animals fed upon 
them, while the remainder, ejected in the form of solid 
or liquid excrements, constitutes farm-yard manure, the 
principal bulk of which, however, consists of straw 
which has served for litter. 

In Germany animals are not fed upon potatoes 
themselves, but upon the refuse from the distilleries of 
potato spirits, which contains all the nutritive substances 
taken away from the soil in the potato crop, together 
with the constituents of the barley-malt that have 
been used in the process of mashing. 

Since the whole of the straw taken away in the 
crops of the preceding rotation is, as a general rule, 
returned to the arable soil in the shape of farm-yard 
manure, the field is, at the outset of the new rotation, 
as rich as before in the conditions for the production of 
straw ; and there exists, under these circumstances, no 
ground for a diminution of the straw-crops. 

With regard to the clover, turnips, potato-waste, 
&c., upon which the stock on a farm is fed, there re- 
mains, as already stated, in the bodies of the horses, 
cattle, tfec, and full-grown animals in general (which 
no longer materially increase in weight), only a very 
small fraction of the constituents of the food consumed ; 
but in the young cattle sent to market, in the bodies of 
the sheep, in the milk and cheese, a portion of these 



220 THE SYSTEM OF FAKM-TAED MANUEING. 

constituents is retained, which is not returned to the 
soil in the farm-yard manure. The loss of phosphoric 
acid and potash which the soil sustains by the sale of 
cattle and of animal products (wool, cheese, &c.), may 
be estimated at one-tenth of the quantity of these min- 
eral constituents contained in the potatoes, turnips, or 
clover ; and even this estimate is, perhaps, too high. 
At all events, it is risking no great error to assume 
that nine-tenths of all the constituents of the clover, 
potatoes, or turnips, are returned to the field in the 
iarm-yard manure ; whence the arable surface soil, 
after manuring, is richer for the new rotation in the 
mineral constituents of potatoes, clover, and turnips, 
than it was before, as the constituents of the two latter 
plants have been brought up from the deeper layers of 
the ground. 

Ihe far greater portion of the active dung-constitu- 
ents is retained by the upper layers of the soil, the 
deeper layers getting back very little of what has been 
taken from them ; the power of the latter, therefore, to 
produce as large crops of clover or turnips as before is 
not restored. 

The soil constituents which the animals have derived 
from the turnips, clover, potatoes, &c., and which re- 
main in their bodies, are very nearly identical, in 
quantity and quality, with those of the cereals ; hence 
the loss sustained by the land may be estimated as 
equal to the corn-crops sold, plus the corn-constituents 
which the fodder-plants have given up to the animals 
on the farm. 

The restoration of the power of a field to produce a 
crop of corn as large as the last naturally presupposes 
that the conditions required for the production of the 
new crop should remain the same in the very layer of 
the soil which supplied the ]) receding crop ; in other 
words, the substances nutritive to corn which were 
taken away must be fully returned to the arable surface 
soil. 

If farm-yard manure contained only the constituents 
of straw and potatoes, and nothing else, manuring a 



THE ELEMENTS OF FOOD IN FAKM-YAKD MANURE. 221 

field ■with it eoiild merely restore the productive power 
of tlie arable soil for straw and potatoes, but not for 
corn. Under these circumstances it would remain as 
rich as before in food elements for straw and potatoes, 
but would be poorer for corn to the extent of the whole 
quantity of corn-constituents taken away in the cro])S. 

If farm-yard manure is to restore the former produc- 
tiveness of a field for corn, it must necessarily contain 
an amount of corn-constituents corresponding to the 
loss sustained, that is to say, as much or even more 
than has been removed. 

The amount of the elements of food for corn con- 
tained in the farm-yard manure naturally depends upon 
the sum of these elements which have passed over into 
manure, from the cattle feeding upon clover or turnips. 

Where this supply exceeds the loss sustained, the 
arable soil is actually made richer in corn-constituents ; 
but in that case it is enriched also in the conditions for 
an increased produce of straw and tuberous plants. 
Where, therefore, the farm-yard manure (by the clover 
or turnip constituents in it) increases the amount of 
phosphoric acid and nitrogen in the arable soil, it in- 
creases, in a much greater projDortion, the quantity of 
potash and lime, and to some extent also that of silicic 
acid ; and since, as already stated, the whole of the 
straw-constituents removed from the field are brought 
back to it in that nuinure, higher crops of corn, straw, 
and potatoes are the natural result. 

This increase of the produce of all cultivated plants 
drawing their principal food from the arable surface 
soil, may go on for a very long time, but in all fields 
it has a certain appointed limit. 

The time comes, sooner or later, for every field, 
when the subsoil (which is to the clover or turnips 
what the arable surface soil is to the cereals), sufiering 
a continued drain upon its stores of phosphoric acid, 
potash, lime, magnesia, &c., begins to lose its produc- 
tive power tor clover or turnips ; and thus the nutritive 
substances, taken away from the arable surface soil in 
the corn crops, are no longer replaced from the store 



222 THE SYSTEM OF FAEM-TAED aiANTIRmG. 

which existed in the deeper layers, and was brought up 
by the clover or the turnips. But the high returns of 
corn given by a field do not necessarily decline with the 
incipient failure of the clover ; for where the arable 
soil of a field has, after every rotation, received from the 
clover or turnips more corn-constituents than it had 
lost by the corn-crop, there may be a gradual accumu- 
lation of an excess of these elements of food sufficient to 
conceal altogether from the farmer the true condition of 
his land. By introducing into his rotation vetches, white- 
clover, and other fodder-plants that derive their food 
from the upper layers of the soil, he succeeds in keeping 
up his live stock, and he indulges in the notion that all 
things go on in his field just as before, when the clover 
or the turnips yielded good crops. This is of course 
simply a delusion, as there is no longer an actual re- 
placeuient of the loss sustained. His high corn-crops 
are now gained at the expense of the nutritive sub- 
stances accumulated in excess in the arable surface soil 
which are set in motion by the fodder-plants introduced 
into the rotation, and are uniformly distributed again 
in the arable soil after each rotation, by means of the 
farm-yard manure. 

His dung-heap may happen to be of larger bulk and 
extent than formerly, but as there is now no further 
supply of nutritive substances brought up from the sub- 
soil or the deeper layers by the clover or turnips, the 
power of the manure to restore the original fertility of 
the arable soil is continually decreasing With the 
ultimate consumption of the excess of corn-constituents 
accumulated in the arable soil, the time comes when 
the corn-crop begins to diminish, whereas the produce 
of straw is comparatively higher than before, as the 
conditions for the formation of straw have been steadily 
increasing. 

Of course, the farmer cannot fail to remark the 
diminution of his corn-crops, ■u'hich induces him to have 
recourse to drainage, to improved tillage, and to the 
substitution of other cultivated plants, in lieu of clover 
and turnips. If the subsoil of his fields will permit it, 



RESULTS OF FABM-YAKD MANITRINO. 223 

lie now includes in bis rotation lucerne and sainfoin, 
whose still longer and more widely spreading roots 
enable tbem to reacb yet deeper layers of tbe ground 
than tbe red clover ; until linally be employs tbe yel- 
low lupine, wbicb may truly be called tbe 'bunger- 
plant,' 

A new increase of produce is tbe result of tbese ' ini- 
provements ' in bis system of cultivation by farm-yard 
manuriiig, wbicb tbe fanner looks upon as a great ad- 
vance. A fresb store of nutritive substances, brougbt 
up from tbe deeper layers of tbe soil, may possibly ac- 
cumulate again in tbe arable surface soil ; but tbese 
deeper layers also will be gradually cxbausted, and tbe 
accumulated store in tbe arable surface soil will also be 
consumed. 

This is the natural termination of cultivation hy the 
system of farm-yard manuring. 

Tbe fields of tbe Saxon experiments aflford very fair 
illustrations of tbe different conditions to wbicb arable 
land in general is brougbt, by a pm'e system of farm- 
yard manuring. 

Tbe field at Cunnersdorf is in tbe first stage, tbe 
Mausegast field in tbe second, tbe fields at Kotitz and 
Oberbobritzscb in tbe tbird stage, of cultivation by 
farm-yard manuring, to wbicb we liave referred. 

At Cunnersdorf tbe arable soil cxbausted by tbe 
preceding cultivation becomes witli every new rotation 
riclier in tbe conditions required for tbe production of 
grain ; not only does tbe clover replace tbe loss sus- 
tained by tbe removal of tbe corn-crops, but a remark- 
able excess of all nutritive substances will gradually 
accumulate in tbe arable soil ; and, after a series of 
years, witli tbe same system of cultivation by farm-yard 
manuring, tbe field will be brougbt to tbe condition of 
the land at Mausegast ; wliicli means, tbat tbe arable 
soil will acquire a bigli productive ])ower for corn and 
otber crops, wbile tbe produce of clover will decrease. 
Tbe fields at Kotitz and Oberbobritzscb most -jirobably 
were in former times in tbe same condition as tbe Mau- 
segast field is at present ; not tbat tliey ever yielded 



224: THE SYSTEM OF FARM-TAED MAI^UEING. 

crops as large as the latter gives, but merely that the 
"unmanured plots have, at some antecedent period, given 
better crops than in the year 1851. Without an addi- 
tional supply of mineral elements derived from mea- 
dows or other fields not included in the rotation, the 
produce must go on continually decreasing, as the sup- 
Y>ly of mineral constituents brought up by the clover 
from the subsoil, in these two places, is far from suf- 
ficient to make up for what is taken away in the corn- 
crojDS. 

In the following calculation it has been assumed 
that of the cro])s obtained, rye and oats were actually 
removed, and of potatoes and clover one-tenth was car- 
ried away in the form of cattle.* 

Cunnersdoi-f. 

Phosphoric acid. Potash, 
lbs. lbs. lbs. 

The arable soil lost by removal of 11 '76 rye-grain. . 10-2 5'5 

" " 2019 oats 15-3 I'l 

" " 3^0 potato crop 2-3 1-lf 

" " -fo clover crop 4-0 20} 

Total loss 31-8 16-3 

The arable soil had returned to it, in -,^0 of 9144 lbs. 

of clover-hay 36-18 95-5 

Balance in excess 4-38 '79*2 



The arable soil of the Cunnersdorf field received, 
accordingly, in the farm-yard manure, more phosphoric 
acid and more potash than had been carried off by the 
corn-crops. 

In this calculation, it is a question of no importance 
how much of the rye or oats was carried off. More 

* The amount of phosphoric acid and potash is estimated in the cal- 
culation as follows : — 

Eye Oats Potatoes. Clover-hay. 

Corn. Straw. Corn. Straw. 

Phosphoric acid .0-864 0-12 0-75 0-12 0-14 0-44 

Potash 0-47 0-52 0-38 0-94 0-58 1-16 

f The quantity of potash is calculated here upon the proportion of 
phosphoric acid in corn, one part by Meight of potash to two parts by 
weight of phosphoric acid. 



MINERAL MATTEKS LOST IN CROPS. 225 

than the field produced could not be carried away, and 
if less -were removed the only efiect would be that phos- 
phoric acid and potash would accumulate all the more 
in the field. 

Mdusegast. 

Phosphoric acid. Potash, 

lbs. lbs. 
The arable soil lost by the rye-grain, barley-grain, 

1^7 potatoes, 1^ clover 35*4 18"1 

The arable soil received in -^^ of the clover crop . . 22 62 "0 

Loss 13-4 Gain 43-9 

Kotitz. 

Phosphoric acid. Potash. 
lbs. lbs. 

The arable soil lost in the rye, oats, and in the -^^ of 

the potatoes and clover 26'4 12-Y 

It received in the clover 8 "5 110 

Loss 17-9 1-7 

The calculation is about the same for the field at 
Oberbobritzsch as for Kotitz. While the arable soil at 
Mausegast, in consequence of the large clover crops pro- 
duced by it, still continues to gain in potash, the corn- 
crops are gradually reducing the rich store of potash in 
the Kotitz field. 

These three fields show the effect of a pure system 
of farm-yard manuring, from which is excluded all sup- 
ply of manure extraneous to the farm itself. 

An additional supply of fodder purchased from 
other farms, or hay grown on natural meadows, answers 
the same purpose as an additional supply of manure. 

It is self-evident that we cannot give more farm-yard 
manure to a field than it produces, unless we take the 
constituents of the manure from some otlier field, which 
in that case must lose just as much as the former field 
gains. 

If we direct our attention to manured fields, we find 
that they give larger corn-crops, and in many cases also 
larger clover or turnip-crops ; the arable soil losing 
more by the removal of the corn-crop, and receiving 

10* 



226 



THE SYSTEM OF FAKM-YAKD MANTJEING. 



more back by the increased produce of farm-yard ma- 
nure, still the ultimate results remain the same. 

In the system of cultivating by rotation of crops, it 
is found that, for a long time, the arable soil grows with 
each period of rotation very much richer than it is by 
nature, in potash as well as in lime, magnesia (the prin- 
cipal constituents of clover and turnips), and in silicic 
acid. 

These substances are the principal conditions for the 
formation of roots and leaves ; their accumulation in 
the soil tends to make the ground rank and prone to 
grow weeds,* as the farmer says, an evil which arises 
as a necessary consequence from cultivation by the sys- 
tem of farm-yard manuring, and which can only be 
met, as he thinks, by a rotation of crops. 

It is generally supposed that the best remedy is the 
hoe ; but though mechanical application may retard the 
developement of weeds for a time, it cannot effectually 
prevent them. The hoe has some share in removing 
them, but not all. 



* The most noxious of these weeds are the wild radish (Raphanus 
raphanistrum), the corn cockle {Agrostenuna cilhago), the corn-flower or 
blue-bottle {Centaurea cyanus), the German camomile {Matricaria chamo- 
milla)^ and the corn camomile (Anthemis arvensis). AH these plants con- 
tain, in their ash, as much potash as is found in clover, and 7 to 18 per 
cent, of chloride of potassium, a salt which forms one of the principal 
constituents of the urine of animals, and which is brought to the field in 
the farm-yard manure. 





II. 


I. 










Matric. 


Matric. 


Anthemis 


Centaurea 


Agrostemma 




Cham. 


cham. 


arvensis. 


cyanus. 


cithago. 


Per cent, ash 


8-51 


9-69 


9-66 


7-32 


13-20 


The ash contains: 












Potash 


25.49 


32-386 


30-57 


36-536 


22-86 


Chloride of potas- 












smm 


18-4 


14-25 


7-15 


11-88 


7-55 


Phosphoric acid . . 


5-1 


7-80 


9-94 


6-59 


6-64 


Phosphate of iron 


2-39 


2-39 


4-77 


2-34 


1-80 



(RiJLiNG, ' Annal. d. Chem. und Pharm.' toI. Ivi. p. 122.) 



SUCCESSION OF CEOPS LN KOTATION. 227 

The succession of crops in rotation is always made 
dependent upon the cereals ; the preceding crops are 
selected of such a kind that their cultivation will not 
injure, but rather improve, the succeeding corn-crop. 
The selection of the particular kind, however, is always 
governed by the condition of the soil. 

In a field abounding in stalk and leaf constituents, 
it is often found useful to have wheat preceded by 
tobacco or rape, rye by turnips or potatoes, since these 
plants by drawing from the soil a large amount of leaf 
and stalk constituents serve to restore a more suitable 
proportion between the straw and corn constituents for 
the futm-e cereal crop, and at the same time to diminish, 
in the arable soil, those conditions which favour the 
growth of weeds. 

The preceding observations relative to the ^jroduce 
given by the Saxon fields, both in the unmanured and 
manured state, atibrd, in my opinion, a perfect insight 
into the nature and results of cultivation by the system 
of farm-yard manuring. In the condition of these fields 
in their several stages, we may see reflected the history 
of agriculture. 

In the first period, or on a virgin soil, corn-crop is 
made to succeed corn-crop, and when the produce be- 
gins to fail, the culture is simply transferred to a fresh 
field. The increasing requirements of the growing 
population, however, gradually put a check upon this 
plan, and compel a steady cultivation of the same sur- 
face ; a system of alternate fallowing is now resorted 
to, and efibrts are made to restore the lost fertility of 
the soil, by manuring with the produce of the natural 
meadows. After a time, this expedient begins to fail, 
and leads to the cultivation of fodder-plants, the sub- 
soil being thus turned to account as an artificial mead- 
ow. The cultivation of fodder-plants proceeds, at first, 
without interruption ; after a time, longer and longer 
intervals are interposed between the clover and turnip 
crops ; finally, the cultivation of fodder-plants comes to 
an end, and with it the system of cultivation by farm- 
yard manuring. The ultimate result is the absolute 



228 THE SYSTEM OF FAKM-YAKD MANURING. 

exhaustion of the soil, inasmuch as the means for in- 
creasing the produce of the soil gradually pass away 
from it by this system. 

Of course, the progress by which these different 
stages are reached is extremely slow, and the results are 
felt only by the third and fourth generation. When 
there are woods near the arable land, the peasant seeks 
to turn the fallen leaves to account as manure ; he 
breaks up the natural meadows which are still rich in 
elements of food for plants, and converts them into 
arable land ; then he proceeds to burn down the forests, 
and to manure his fields with the ashes. When the 
gradual exhaustion in the productive power of the land 
has led to a corresponding decrease in the population, 
the peasant cultivates his land once every two years 
as in Catalonia, or once every three years as in Andalu- 
sia.* 

No intelligent man who contemplates the jDresent 
state of agriculture with an unbiased mind, can remain 
in doubt, even for a moment, as to the stage which hus- 
bandry has reached in Europe. We find that all coun- 
tries and regions of the earth where man has omitted to 
restore to the land the conditions of its continued fer- 
tility, after having attained the culminating period of 
the greatest density of population, fall into a state of 
barrenness and desolation. Historians are wont to 
attribute the decay of nations to political events and 
social causes. These may, indeed, have greatly contrib- 
uted to the result ; but we may well ask whether some 
far deeper cause, not so easily recognised by historians, 



* The Emperor Charles V. gave orders that the meadows recently 
turned into arable land should be restored to their former condition. Even 
before the time of Charles V. orders of the same nature had been issued by 
the first Catholic Kings, and at a still earlier period by Pedro the Cruel of 
Castile. In the beginning of the fifteenth century, Henrique of Castile pro- 
hibited the exportation of cattle, on pain of death ; and as early as the 
commencement of the fourteenth century, King Alonzo Onzeno had issued 
ordinances for the preservation of meadows and pastures. (' Bilder aus 
Spanien von Karl Freiherrn von Thienen, Adlerflycht.' Berlin : Bunker, 
p. 241.) All in vain ! for what avails the power of even the mightiest 
monarchs against the irrepressible action of a law of nature ? 



FALSE DOCTEINES. . 229 

has not produced these events in the lives of nations, 
and whether most of the exterminating wars between 
different races may not have sprung from the inexorable 
law of self-preservation ? Nations, like men, pass from 
youth to age, and then die out — so it may appear to the 
superficial observer ; but if we look at the matter a 
little more closely, we shall find that, as the conditions 
for the continuance of the human race which nature has 
placed in the ground are very limited and readily 
exhausted, the nations that have disappeared from the 
earth have dug their own graves by not knowing how 
to preserve these conditions. Nations (like China and 
Japan) who know how to preserve these conditions of 
life do not die out. 

Not the fertility of the earth, but the duration of 
that fertility, lies within the power of the human will. 
In the final result, it comes very mucli to the same 
thing, whether a nation gradually declines upon a soil 
constantly diminishing in fertility, or whether, being a 
stronger race, it maintains its own ex-istence by exter- 
minating and taking the place of another people upon a 
land richer in the conditions of life. 

It can hardly be ascribed to caprice or chance that 
the cultivator in the liuertas of Valencia obtains three 
crops yearly from the same soil, while in the immediate 
neighbouring district the ground is tilled only once in 
three years ; or that the Spaniards burned down forests 
in sheer ignorance, in order to use the ashes to restore 
the fertility of their fields. (See Appendix G.) 

Everyone who is at all acquainted with the natural 
conditions of agriculture, must perceive that the method 
of culture practised for centuries in most countries could 
not but inevitably impoverish and exhaust even the 
most fruitful lands ; can it then be supposed that there 
will be any exception in the case of cultivated lands 
in Europe, and that like causes will not produce like 
effects ? 

Under these circumstances, is it right or reasonable 
to pay any attention to the doctrines of superficial wise- 
acres, who, with their wretched chemical analyses find 



230 THE SYSTEM OF FAKM-YAED MANUKING. 

an inexhaustible supply of nutritive substances in any 
given soil, even in one which can no longer produce 
clover, turnips, or potatoes, and yet may be rendered 
capable of producing these plants by manuring with 
ashes or lime in the right places ? 

In the face of the daily experience which shows that 
the corn-fields, if they are to remain fruitful, must be 
manured after a short series of years, it is a crime against 
human society, a sin against the public welfare, to dis- 
seminate the doctrine that the fodder-plants, which fur- 
nish manure to the corn-fields, will constantly find upon 
the field the conditions of their own growth, that the 
law of nature applies to one kind of plant only, and has 
no bearing upon the other. The teaching of these men 
has no other result than to keep agriculture in the low 
position which it now occupies. In England it is a mere 
mechanical handicraft, and in that country manure is 
regarded as merely the oil which smoothes the wheels 
and keeps the machine in motion. 

In Germany agriculture is a jaded horse, treated 
with blows instead of fodder ; nowhere is its real beauty 
and the intellectual aspect of its pursuit recognised. 
Not merely for its utility, but on account of this very 
intellectual nature of its pursuit, it stands above all 
occupations ; and its practice procures, to the man who 
understands the voice of nature, not only all the advan- 
tages for which he strives, but also those pleasures which 
science alone can afford. 

In human society, ignorance is undoubtedly the 
fundamental, and therefore the very greatest evil. The 
ignorant man, however rich he maybe, is not protected 
from poverty by his wealth ; wliile the poor man, who 
has knowledge, becomes rich by its means. Uncon- 
sciously to the ignorant farmer, all his industry, care, 
and toil only hasten his ruin ; liis crops gradually di- 
minish, and at length his children and grandchildren, 
no wiser than himself, are unable to maintain them- 
selves upon the homestead where they were born ; their 
land passes into the hands of the man who has knowl- 
edge; for by knowledge capital and power are acquired, 



COKN NOT INCREASED BY FARM- YARD MANURING. 231 

and by these, as a matter of course, the helpless arc ex- 
pelled from the inheritance of their forefathers. 

As an animal cannot care for himself, the law of 
nature takes care of him, and is his master ; but not so 
with man, who, if he understands the intentions of God 
in his creation, is master of the law of nature, wliich 
yields to him a complete and willing obedience. The 
animal brings into the world his perceptions and in- 
stincts, which grow up with his growth, and without 
any effort of his own ; but to man the Creator gave 
the gift of reason, and this distinguished him from the 
brutes. This is the divine talent, which he should put 
out to interest, and of which it is said, ' He that hath, 
to him shall be given ; but from him that hath not, 
shall be taken away even that which he hath.' It is 
only the interest procured by means of this ' talent ' 
that gives man power over the forces of the earth. 

Error arising from want of knowledge is excusable, 
for no one adheres to it after recognising its existence ; 
and the struggle between error and dawning truth arises 
from the natural striving of men for knowledge. In 
this contest truth must grow stronger, and if error pre- 
vails, this only proves that truth has yet to grow, not 
that error is truth. 

At all times the ' better ' has always been the ene- 
my of the ' good ; ' but men do not comprehend for all 
that why, in so many cases, ignorance is the enemy of 
reason. 

There is no profession which for its successful prac- 
tice requires a larger extent of knowledge than agricul- 
ture, and none in which the actual ignorance is greater. 

The farmer who practises the system of rotation, 
depending exclusively upon the ajjplication of farm-yard 
manure, needs very little observation, nay only to open 
his eyes, in order to be convinced, by innumerable proofs, 
that whatever may have been the outlay of labour and 
industry applied to the production of farm-yard manure, 
his fields have not been thereby increased in the jDower 
of bearing crops. 

If farm-vard manure was actually able to render a 



232 THE SYSTEM OF FAKM-YAED MANURING. 

field permanently richer in nutritive substances than 
it is by nature, Ave might expect that a course of manur- 
ing for fifty years would necessarily produce a steady 
increase in the crops. 

Now, if farmers w^ho practise the system of rotation, 
laying aside all bias and prejudice, would compare their 
present with their former crops, or with those obtained 
by their fathers or grandfathers, none of them would 
be able to say that the crops have increased, and only 
few that the average has remained the same. Most of 
them would find, that on the average, the straw-crops 
have turned out higher, but the corn-crops lower, and 
proportionately lower than they formerly were higher ; 
and that the surplus money which their parents gained 
by the former high crops, the result of their improve- 
ments, as they supposed, must now be paid out again, 
to purchase manuring substances, which, as people 
formerly thought, could be ' produced.' ISTow, how- 
ever, they begin to learn that though such substances 
may be produced for a time, they cannot be reproduced 
in perpetuity. 

In like manner, the farmer whose richer ground has 
enabled him to carry out the three-field system, and 
whose rich meadows guarantee a supply of manure, 
who obtains as abundant harvests and as large a weight 
. of corn as the farmer who adopts the system of rotation, 
and thus surmises that his management has procured 
what the ground gives of its own free will, will inevi- 
tably discover that his fields may be exhausted of the 
conditions of their fertility, and that it is quite erroneous 
to suppose that all the farmer's art consists in convert- 
ing manure into corn and flesh. 

A simple law of nature regulates the permanence 
of agricultural produce. If the amount of produce is 
in proportion to the surface presented by the sum total 
of nutritive substances, in the soil, the jperTnanence of 
the crops will depend upon the maintenance of that pro- 
portion. 

This law of compensation, the replacement of nutri- 
tive substances which the crops have carried away from 



RECORDS OF CHARLEMAGNE. ' 233 

tlie soil, is the foundation of rational husbandry, and 
must, above all things, be kept in view by the practical 
farmer. He may renounce the hope of making his land 
more fruitful than it is by nature, but he cannot expect 
to keep his harvests up to their average if he allows the 
necessary conditions for them to diminish in his land. 

All those farmers who cherish the notion that the 
produce of their fields has not declined, have not hither- 
to been able to appreciate the force of this law. As- 
suming that they have an excess of nutritive substances 
to deal with, they think they may continue drawing 
upon it, until a failure becomes visible, and then they 
fancy it will be time enough to talk of compensation. 

Tliis view results from want of understanding the 
nature of their own acts. 

There surely can be no doubt that to manure a field 
which already contains an excess of nutritive substances 
is opposed to a rational system of cultivation ; for what 
end could be gained by increasing the nutritive sub- 
stances in a field where a portion of the elements already 
existing cannot, on account of their mass, come into 
operation ? 

But how can sensible men talk of excess when they 
are obliged to use manure in order to keep up their 
harvests, and when their crops decline if they employ 
no manure ? 

The simple fact, say others, that in certain districts, 
as in Rhenish Bayaria, agriculture has flourished since 
the time of the Romans, and that the ground there is 
just as rich, nay, gives higher crops than in other lands, 
is a proof how little reason there is to fear want or ex- 
haustion by continued culture ; for if such a thing were 
likely, it would make itself manifest there sooner than 
elsewhere. 

But in the cultivated lands of Europe agriculture 
is at all events still very young, as we know with the 
greatest certainty from records of the time of Charle- 
magne. His ordinances respecting the management 
of his own estates {capitulare de villis vel curtis im- 
peratoris), wherein directions are given to the stewards. 



234 THE SYSTEM OF FAKM-YAED MANUKING. 

as also the official reports to the Emperor (^specimen 
hreviai'ii rerum ■fiscaliiun Caroll Ilagni), sent in by 
inspectors expressly appointed to survey those estates, 
are irrefragable proofs that tliere was then no agricul- 
ture worth the name. Very little is said in the (Japitu- 
lare about the cultivation of corn, with the exception 
of millet. It is reported in the Breviarium,, that at 
Stefans worth (a domain of the Emperor), comprising 
740 acres {jurnales) of arable land and meadow, capa- 
ble of supplying 600 cartloads of hay, the commissioners 
found no corn in store, but on the other hand a large 
number of cattle, 27 sickles great and small, and only 
seven broad hoes, to till 740 acres of land ! 

Upon another estate were found 80 baskets of last 
year's spelt, equivalent to 400 lbs. of flour (=1-^ bushel, 
or somewhat more than 3 hectolitres), 90 baskets of 
spelt of the current year, from which 450 lbs. of flour 
could be made. On the other hand, there were 330 
hams ! 

The crop or stock upon another domain amounted 
to 20 baskets of spelt (=100 lbs. of flour) of the preced- 
ing year, and 30 baskets of spelt, of which <??ie was used 
for seed. 

It is easy to see that in those days the breeding of 
cattle was the chief object, and that the cultivation of 
corn occupied a very subordinate position in husbandry.* 
A deed of the period shortly after Charlemagne says 
on this point : ' Every year, three yokes of land upon 
an estate ' should be ploughed and sown with seed fur- 
nished by the lord of the manor. (See ' die Getreide- 
Arten nnd das Brod von Freih. von Bibra.' Nurem- 
berg : Schmid. 1860.) 

Hence we possess not a single trustworthy proof that 
any one field in Germany or France (perhaps we may 
make an exception in favour of Italy) has served for 
tlie cultivation of corn from tlie time of Charlemagne 
to our own age ; and the argument for the inexhausti- 

* It is worthy of remark that Charlemagne introduced, upon his 
estates, the three-field system, with which he had become acquainted in 
Italy. 



EXHAUSTION OF KHENISH BAVARIA. 235 

bility of land is almost childish, because it assumes that 
corn may be continuously taken from a field, 'without 
redoi^ing the conditions of reproduction. A field docs 
not necessarily become unfruitful for corn because it 
has yielded large corn-crops ; but it ceases to yield corn- 
crops if it does not receive compensation for the corii- 
constituents which have been removed. This compen- 
sation is facilitated by the breeding of cattle, in propor- 
tion to the extent to which this is carried, and especially 
when the cultivator is acquainted wdth the operation 
of manure. In the time of Charlemagne this was well 
known, for the winter-crops were manured with dung, 
distinguished as cattle-dung (called gov) and horse-dung 
{dost or deist). Besides, the practice of marling w^as 
then common in Germany. 

"With regard to the special instance of Rhenisli 
Bavaria as proving the inexhaustibility of the soil, I 
had an opportunity last autumn, at a meeting of the 
Society of Naturalists at Spires, of making particular 
inquiries about the actual condition of the neighbom'- 
hood. Khenish Bavaria, from the slopes of the Hardt 
mountains to the Rhine, comprises a district of great 
fertility : the region is inhabited by an extremely in- 
dustrious population, distributed in small towns and 
villages. Almost every artisan, even to the tailor and 
shoemaker, possesses a small plot of ground, on which 
he raises his potatoes and vegetables. The ex]3ort of 
corn from this district is never thought of, but on the 
contrary corn and a large quantity of manure are im- 
ported from Mannheim, Heidelberg, and elsewhere. The 
manuring substances obtained from the houses of the 
towns and villages are carefully treasured and employed, 
so that there can be no fear of exhaustion, since the 
removed nutritive substances are restored to the fields. 
In spite of all this, in no part of Germany is the want 
of manure more felt than there. On the highways chil- 
dren are constantly seen with little baskets, following 
the horses and swine, to gathei" the manure dropped by 
those animals. In the year 1849, during the political 
agitation in the Palatinate, the peasants had no more 



236 THE SYSTEM OF FAKM-YAKD MANTJKIKG. 

urgent request for the improvement of their condition 
to lay before the magistrates, than a petition to be al- 
lowed to collect ' forestings,' that is, to carry off the 
natural manure from the forests for the benefit of their 
fields. They urged that without this (very pitiful) ad- 
dition to their manure, the future prospects of agricul- 
ture in the Palatinate Avere endangered. In fact, a 
great quantity of manure is laid out upon the vineyards 
and tobacco fields, which give none in return ; hence 
the increasing Avant. 

There can be no doubt that in the earliest periods 
most of our cultivated fields gave a succession of abun- 
dant crops, without manuring, as in the case even now, 
with many fields in the United States of America. But 
no fact has ever yet been more clearly established by 
experience than this, that in the course of a few genera- 
tions all such fields are found perfectly unsuited for the 
growth of wdieat, tobacco, and cotton, and that they re- 
cover their fertility only by manuring. 

I know full well that recorded facts have as little 
weight with ignorant 'practical men' as those of politi- 
cal history with practical statesmen, who also act ac- 
cording to ' circumstances and contingencies,' and are 
simply led when they fondly believe they lead. Still, 
the reflecting mind cannot fail to be struck by the cir- 
cumstance, that it is just in countries where the land is 
most positively known to have given for above 4000 
years, without manuring by the hand of man, an unin- 
terrupted succession of abundant crops, that the full 
action of the great law of restitution is most clearly 
seen. 

We know, most positively, that the corn-fields in 
the valley of the Nile and the basin of the Ganges re- 
main permanently fruitful, simply because nature has - 
taken upon herself to restore the lost condition of pro- 
ductiveness to the soil in the mud deposited by the 
inundation of these rivers which gradually raises the 
land. 

All the fields that are not reached by the river lose 
their productiveness unless manured. In Egypt, the 



THE SOIL KOT INEXHAUSTIBLE. 23 Y 

amount of the crop to be expected is calculated from 
the height of the water of the JS^ilc; and in the East 
Indies a famine is the inevitable consequence whenever 
there happens to be no inundation. 

Xature herself, in these striking instances, points 
out to man the proper course of proceeding for keeping 
up the productiveness of the land. (See Appendix 11.) 

The notion of our ignorant jiractical husbandmen, 
that the soil contains ample store of the elements of food 
to enable them to pursue their system of agriculture, is 
due partly to the excellent quality of the land, but also 
to their skill in robbing it. Tlie man who attempts to 
gain money by filing the weight of one gold piece from 
a thousand, cannot plead, in extenuation, that it is re- 
marked by no one, but if discovered he is punished by 
the law ; for everybody knows that the fraudulent act, 
repeated a thousand times, would ultimately leave 
nothing of the gold pieces. A similar law, from which, 
moreover, there is no escape, punishes the agriculturist 
who would make us believe that he knows the exact 
store of available food elements in his land, and how far 
it will go ; and who deceives himself when he fancies 
he is enriching his field by bestowing on the arable sur- 
face soil the matters taken from the deeper layers. 

There is another class of agriculturists consisting of 
men with a small stock of knowledge joined to a limited 
understanding, who, indeed, fnlly recognise the law of 
restitution, but interpret it after their own fashion. 
They assert and teach that part of the law only, and 
not the whole, applies to cultivated fields ; that certain 
constituents, unquestionably, must be restored to the 
soil to keep up its productiveness, but that all the others 
are found in the earth in inexhaustible quantities. Tliey 
generally base their opinion upon some unmeaning 
chemical analysis, and demonstrate to the simple agri- 
culturist (for whom alone such discjuisitions are intend- 
ed) how rich his fields still are in some one or other of 
the mineral constituents, and for how many hundred 
thousand crops the store will still sufHce ; as if it could 
be of the least use for any one to know what the soil 



238 THE SYSTEM OF FAEM-YAKD MANFEING. 

contains, if the amount of the available food elements 
that serve to produce the crops, which is the really im- 
portant point, cannot be determined. 

AVith such absurd assertions they absolutely hood- 
wink our ' practical ' farmers, who, but for them, might 
see clearly into matters, but who appear only too will- 
ing to accejjt any assertion that will only leave them at 
peace, and save them the trouble of ' thinking.' 

I remember a case where a swindler offered to sell 
to a wealthy gentleman, at a high price, a mine of 
almost pure oxide of aluminium, after having shown 
him, from chemical works, that oxide of aluminium was 
indispensable for the production of the metal alumin- 
ium, the market price of which was as much as 41. per 
pound, and that the ore of the mine ofl'ered for sale con- 
tained nearly 80 per cent, of that valuable metal. The 
purchaser was not aware that the ore in question is gen- 
erally known as ' pipe-clay,' an article of almost nom- 
inal value, and that the high price of the metal arises 
from the many changes through which the oxide has to 
pass to effect its reduction to the metallic state. 

It is generally the same with the great stores of pot- 
ash in the soil. The alkali in the ground, to answer 
the intended purpose, must, by the agriculturist's art, 
be converted first into a certain form, in which, alone, 
it is available as food for plants ; and if he does not 
understand how to effect this conversion, all the potash 
in his soil is of no earthly use to him. 

The notion that the farmer need only restore to his 
land certain substances, without troubling himself about 
the rest, might not be prejudicial if those who enter- 
tained it confined the application to their own farms ; 
but, as a matter of instruction to others, it is untrue 
and quite exceptionable. It is calculated for the low 
intellectual standard of the practical man, who, if he in 
any way succeeds, by certain alterations, in his system, 
or by the use of certain manuring agents in obtaining 
better results than another, attributes his success to his 
own sagacity rather than to the superior quality of his 
land. He does not even know that the other has tried 



IGNOEANT PRACTICAL MEN. 239 

the very same plans as himself, only without attaining so 
favourable a result. Our ignorant practical husband- 
man starts upon the assumption that all tields are the 
same in condition as his own, and that, therefore, the 
same system which answers on his farm ought to do 
equally well on every other ; that the manure which he 
finds useful ought to be equally useful to others ; that 
the deficiencies in his field are the same in all other 
fields ; that what he exports from his land, others ex- 
port from theirs ; and what he is called upon to restore 
to his soil, others are equally called upon to restore to 
theirs. 

Although he knows next to nothing of the condition 
of his own land, with which it would, indeed, require 
many years of careful observation to become familiar, 
and is most profoundly ignorant about the condition of 
the land in any other part ; although he never has troub- 
led himself with reflecting upon the causes of his suc- 
cess in the cultivation of his fields, and is quite aware 
that the advice of agriculturists from other parts, 
respecting manuring, rotation of crops, and the general 
treatment of his own land, is not of the slightest use to 
him, because, as he has found, it is not at all applicable 
to his district ; yet all this does not prevent him from 
wanting to instruct others, and persuade them that his 
system is. the only true one, and that they need only do 
as he does to obtain equally favourable results. 

The foundation of all such views is a total miscon- 
ception of the nature of the soil, the condition and com- 
position of which present an infinite variety of shades. 

The fiict that numy fields that happen to be rich in 
silicates, and in lime, potash, and magnesia, are, by the 
growth of corn upon the common farm-yard manuring 
system, drained only of phosphoric acid and nitrogen, 
and that the fiirmer need only look to the replacement 
of these matters without troubling his mind about the 
rest, has already been fully discussed. This fact no one 
can dispute : but it is utterly inadmissible to apply it 
to the case of other fields, and to make other farmers be- 
lieve that they, too, need not trouble their minds about 



24:0 THE SYSTEM OF PAEM-YAED MANURING. 

supplying to their land potash, lime, magnesia, or silicic 
acid, and that salts of ammonia and superphosphate of 
lime will suffice to restore the productiveness of all 
exhausted fields. 

A farmer may, therefore, be quite justified in con- 
sidering tliat his field can never grow poorer in potash 
because he never takes any from it, or that it actually 
contains a superabundance of potash since every rota- 
tion tends to accumulate in the soil a fresh amount of 
that ingredient ; but it is childish of him to think him- 
self justified by this circumstance in assuring another 
agriculturist, about whose system of cultivation he 
knows nothing, that the fields of the latter equally con- 
tain a superabundance of potash. 

There are millions of acres of fertile land (sand and 
clay-soil), in which the proportion of lime or magnesia 
in the soil does not exceed that of phosphoric acid, and 
where provision must be made for replacing the former 
as well as the latter. Again, there are millions of acres 
of fertile land, which, like calcareous soils in general, 
are exceedingly poor in potash, and become absolutely 
barren without a proper supply of this ingredient. 

There are, on the other hand, millions of acres of 
fertile fields abounding so richly in nitrogen that any 
additional supply of that element would be mere waste. 

Ashes will not promote the growth of clover on fields 
abounding in potash, whilst the application of manur- 
ing agents containing phosphoric acid will have that 
efiect ; on the other hand, ashes will make clover grow 
on land deficient in potash, where bone-earth proves 
useless ; and a simple supply of lime containing mag- 
nesia will often suffice to restore the productiveness for 
clover where the land is deficient in lime and mag- 
nesia. 

When a farmer, besides corn ?.nd flesh, grows and 
sells other produce, the nature of the required supply 
of mineral elements is thereby necessarily altered. In 
the average potato produce of three hectares of land 
Ave take away the seed-constituents of four wheat crops, 
besides about 600 lbs. of potash, and in the average 



ArA'n'EUS TO RK JiKSTOKED VARY. 241 

tni-nip produce of three hectares the seed-constituents 
of four wheat-crops, besides about 1000 lbs. of potash. 
A supply of phosphoric acid alone will not sutiice, in 
this case, to keep up the pnithictiveuess of the land. 

The grower of commercial plants, such as tobacco, 
hemp, flax, the vine, etc., nnist in like manner strictly 
attend to the law of restitution, which, properly inter- 
preted, does not imply that he should bestow the same 
anxious care upon the replacement of all constituents 
alike which have been taken away in the crops. It 
would, for instance, be the height of absurdity to re- 
quire the tobacco planter who grows his crops on a lime 
or marl soil, to replace the lime carried off in the leaves 
of the plant. But it tells him that not all that goes by 
the name of manure is useful for his fields, and it shows 
him the difference between manures : it informs him of 
the loss inflicted upon the soil by the preceding crop, 
and the supply required to insin'e future harvests ; it 
teaches him never to allow himself to be guided in his 
proceedings by the opinions of persons who do not take 
the slightest interest in him and his land, but always to 
act upon his own observations. A careful study of the 
■weeds that spring up spontaneously in his flelds may 
fretpicntly prove more useful in this respect than a heap 
of hand-books on agriculture. 

If after the foregoing statements the condition of 
the cultivated land in Europe, and the decline towards 
which agriculture is tending by the prevailing s3-stem 
of farm-yard manuring, should still be a matter of 
doubt to many persons unacquainted with the natural 
sciences, and who trust only to definite numbers as 
palpable facts, that doubt may, perhaps, be removed 
by statistical data on the corn produce of the land in 
different parts of Germany, which have been collected 
partly by order of the government. 

For a correct appreciation of the importance of 
these data in the matter, it is necessary in the first 
place to understand clearly what is meant by an 
* average ' crop. By this term is designated the aver- 
age produce, expressed in numbers, of a field, or a 
11 



242 THE SYSTEM OF FAKM-YAED MANUKING. 

number of fields, or all the fields of a district or coun- 
try. Tlie figure which represents it is found by adding 
together the produce of all the fields for a number of 
years, and dividing the sum total by the latter. There 
is accordingly a special average produce for every dis- 
trict, by which the next year's crop is judged. Thus 
we talk of a full, or a half, or a three-qnarter average, 
as the produce happens to come np to the calculated 
average, or fall one-half or one quarter below it. 

The question as to the actual condition of our corn- 
fields may therefore be put thus : Has there been any 
change in the figure which at any previous period ex- 
pressed the average produce of the land, and in what 
sense ? Is that figure higher now than formerly, or has 
it remained the same or fallen ? If the figure is higher, 
this is of course a sign of an improved condition of the 
land ; if it remains the same, the condition has under- 
gone no change ; and if it is loAver, there can be no 
doubt tliat the condition of tlie land in that district has 
declined. 

I select for my purpose the statistical data of the 
produce of the Hessian Rhine district, one of the most 
fertile provinces of the Grand Duchy of Hesse, with an 
excellent wheat soil, and inhabited by a most indus- 
trious and generally well educated population. (' Sta- 
tistische Mittheilungen fiber Rheinhessen, von F. Dael, 
DLL.' Mayence : 1849. Flor. Kupferberg.) 

These data embrace a period of fifteen years, from 
1833 to 1847 ; they refer accordingly to the time when 
guano was not yet nsed as manure in Germany, The 
use of bone-earth was at that time also still very limit- 
ed, and hardly worth taking into account. 

A produce of eleven grains of wheat to every two 
grains sown, of five and a half accordingly, was held to 
be an average crop for the Hessian Rhine district. (20 
malters = 14 bushels = 5120 hectolitres per hectare = 
2-471 English acres.) 

Taking the figure 1 to express an average crop, the 
amount of produce reaped in the Rhine district of 
Hesse was : — 



MEAN OF AVERAGE CROPS IN RHINE HESSE. 243 



:S33. 


1334. 


1335. 


1836. 1837. 


1838. 


1S39. 


0-86 


0-78 


0-88 


0-72 0-88 


0-73 


0-Gl 


1840. 


ISll. 


1342. 


1343. 1844. 1815. 


1346. 


1847. 


MO 


0-40 


0-90 


0-74 1-02 0-C3 


0-75 


0-88 



which gives a mean for the fifteen years of 0-79 of the 
former average. 

The productiveness of the wheat land in the Rhine 
district of Hesse has therefore declined somewhat more 
than one-fifth. 

I know all that may be urged against the accuracy 
of these figures severally, and their trustworthiness col- 
lectively ; but if they contain errors, the impartial 
observer must see that these must tend to the plus as 
well as to the minus side, and that it would be most 
extraordinary in the presence oi plus errors that all the 
estimates should have fallen out on the minus side. 

Tliere is, however, a very simple, and at the same 
time infallible and irrefutable, proof of the correctness 
of the conclusions drawn from these figures, in the fact 
that the cultivation of wheat is on the decrease, that of 
rye on the increase, in Rhine Uesse, and that many 
fields on which wheat was formerly grown are now 
turned into rye fields. 

Properly understood, the change from wheat to rye 
always argues a deterioration in the quality of the soil ; 
the farmer begins to grow rye in a wheat field only 
when the latter no longer gives remunerative wheat 
crops. 

In Rhine Ilessc, a 4.} fold produce of rye is consid- 
ered an average cro]) ; a wheat soil, therefore, capable 
of giving only four-fifths of an average wheat-crop, can 
produce a full average rye-crop. 

Now the average produce of rye in the fifteen j^ears 
is 0-96, which pretty nearly corresponds with the full 
average. 

For spelt, the mean was 0*79 of the average ; for 
barley, 0-88 ; for oats, 0-88 ; for peas, 0-67 ; fo'r pota- 
toes, on the other hand, 0*98 ; and for colewort and 
turnips, 0-85. 

Tlie statistical data collected in Prussia and Bava- 



24:4: THE SYSTEM OF FAEM-YAED MANURING. 

ria, which ai'e most reliable, give the same result ; and 
I have not the slightest doubt that it would hold equally 
true with France and other countries, England includ- 
ed. The visible gradual detei'ioration of the arable soil 
cannot but command the serious attention of all men. 
who take an interest in the public welfare. It is of the 
utmost importance that we do not deceive ourselves re- 
specting the danger, indicated by these signs, as threat- 
ening the future of the populations. An impending 
evil is not evaded by denying its existence or shutting 
our eyes to the signs of its approach. It is our duty to 
examine and appreciate the signs : if the source of the 
evil is once detected, the first step is thereby taken to 
remove it for ever. 



CHAPTER yi. 



GUANO. 

Composition compared with that of seeds ; small amount of potash in it ; its ac- 
tion — Guano and bdiiecarth, simil:irity of thtir active inL'redieiits — Guano 
acts quicker than bune-earth, or a mixtureof tlie latter and aninioniacal salts ; 
reason of tins — Oxalic acid iii Peruvian guano ; tlie jihosplioric acid rendered 
soluble by its means — Peruvian iruano, its eflect on tlie cultivation of corn — 
Moist guano lo^e8 ammonia — MoiKleniiig guai.o with water acidulated with 
sulphuric acid ; etfect — Inactivity of guano in dry and very wet weatlier — 
Rapidity of its action as a manure, on what dependent — Comparison of iho 
ell'ect of farm-yard n)aruire and u'uaro ; effect produced liy niixii g tlie two — 
Guano on a tield rich in ammonia — Increased produce by guano, what it pre- 
supposes—Exhaustion of ilic soil by continuous use of guano — Mixture of 
guano with gypsum and with sulphuric acid — The Sason agricultural experi- 
ments; their results. 

PERUYIAjS' giiano generally contains 33 to 34 per 
cent, of incombustible, and G6 to 67 per cent, of 
volatile and combustible ingredients (water and ammo- 
nia). The latter consist principally of uric acid, oxalic 
acid, a brown matter of uncertain composition, and 
guanine. ITie uric acid amounts occasionally to as 
much as 18 per cent., the oxalic acid generally to 8 or 
10 per cent, of the weight of the guano. The relation 
of uric acid to vegetation is not known, but it is hardly 
likely that this substance can have a perceptible share 
in the fertilising action of guano. To account for this 
action, then, we have only tlie ammonia and the incom- 
bustible constituents left to consider. An analysis of 
two sam])les of guano, made by Dr. Mayer and Dr. 
Zoeller, in my own laboratory, showed 100 parts of 
guano ash to contain : — 

Potash 1 -56 to 2-03 

Lime S4-00 " 37-00 

Magnosiiv 2-56 " 2'00 

Phosphoric acid 41 00 " 40-00 



216 GUANO. 

If we compare with this the composition of the ashes 
of various seeds, we see at once that the incombustible 
constituents of guano do not altogether replace the soil 
constituents carried o£f in the seeds. 

In 100 parts of seed ash are contained, — 

Wheat. Peas and beans. Kape. 

Potash 30 40 24 

Lime 4 6 10 

Magnesia 12 6 10 

Phosphoric acid 45 36 36 

The principal difference between the ash of guano 
and that of these seeds lies in the deficiency of potash 
and magnesia in the former. 

Agriculturists are generally agreed about the neces- 
sity of potash for vegetation, and that a supply is re- 
quired by fields poor in that ingredient, or drained of 
it ; but the question as to the importance of magnesia 
for seed formation has not, as yet, met with the same 
attention, and special experiments in this direction 
would be very desirable. The fact that much more 
magnesia is found in the seeds than in the straw unmis- 
takably shows that it must play a definite part in the 
formation of the seed, which might, perhaps, be ascer- 
tained by a careful examination of seeds of the same 
variety of plants containing different amounts of mag- 
nesia. It is a well-known fact that the seeds of the 
several species of cereals having the same proportion of 
nitrogen, do not always contain the same nitrogenous 
compounds, and it is possible that the nature of the lat- 
ter may, in the formation of the seeds, be essentially in- 
fluenced by the presence of lime or of magnesia, so that 
the differences in the proportions of both of these alka- 
line earths may have a certain connection with tlie pres- 
ence of the soluble nitrogenous compounds (albumen 
and casein), or of the insoluble (gluten or vegetable 
fibi'ine). Of course, the quantity of potash and soda 
present would have to be taken into account in an in- 
vestigation of the kind. The fertilising action of guano 
is generally attributed to the ammonia in it, and to the 
other ingredients rich in nitrogen ; but accurate experi- 



OXALATE OF AMMONIA IN GUANO. 217 

raents made to cliiciclate this point, by the General 
Committee of the Agricnlturai Soeiety of Bavaria, 
which we shall hereafter have occasion to mention, 
have shown that whilst the nse of guano was found, in 
many cases, to increase very considerably the produce 
of corn and straw of a field, the application of an ani- 
moniacal salt containing an amount of nitrogen cor- 
responding to that in the guano produced no perceptible 
effect on the crop of the same cereal, grown in the 
same year, upon another plot of the field, when com- 
pared with the produce of a third unmanurcd plot of 
the same field. 

Though the part which the ammonia in the guano 
plays, in many cases, in increasing the produce, cannot 
be questioned ; yet it is equally certain, on the other 
hand, that in numy other instances the fertilising action 
of guano must be attributed principally to its other con- 
stituents. 

If the ash of guano is compared with calcined bones, 
or bone-earth, it is found that the difference between 
the two is not very great ; yet an amount of bone-earth 
containing the same proportion of earthy phosphate as 
in guano, or even two to four times that quantity, has 
not the same action as the latter manure. Even a mix- 
ture of bone-earth with ammoniacal salts in sufficient 
proportion to make the amount of nitrogen and phos- 
phoric acid equal to that contained in the guano, though 
more efiicacious than bone-earth alone, has still a dif- 
ferent action from guano. The great distinction be- 
tween the two lies in the greater rapidity of the action 
of the guano in the first year, and often even in tlie 
course of a few weeks, whilst in the year after it is 
barely perceptible ; that of the bone-earth, on the other 
hand, is comparatively slight in the first year, but in- 
creases in tlie following. 

The cause of this diiFerence of action is the oxalic 
acid in Peruvian guano, wliich often amounts to from 6 
to 10 per cent. If guano is subjected to lixiviation, the 
water dissolves sulphate, phosphate, and oxalate of am- 
monia, which latter salt crystallises out abundantly 



248 



GUANO. 



npon evaporating the solution. But if the gnano is 
moistened with water, without hxiviating, and is then 
left to itself, it is found, upon extracting with water 
portions of the mixture from time to time," that the pro- 
portion of the oxalic acid in the solution gradually de- 
creases, whilst that of the phosplioric acid increases. A 
decomposition takes place in this moistened condition 
of the guano, through the agency of the sulphate of am- 
monia, by which the phosphate of lime is converted into 
oxalate of lime and phosphate of ammonia. Peruvian 
guano is, in this respect, a very remarkable mixture, 
which could scarcely have been more ingeniously com- 
])ounded for the purposes of the nutrition of plants ; for 
the phosphoric acid in it becomes soluble only in a 
moist soil, tlirough which it then spreads in form of 
phosphate of potash, phosphate of soda, and phosphate 
of aunnonia. 

The action of guano may rather be compared to a 
mixture of superphosphate of lime, ammonia, and salts 
of potash, which, indeed, in many cases, is equal to it. 
On a soil abounding in lime, guano is, however, decid- 
edly more advantageous than superphosphate of lime, 
since the latter, upon coming in contact M'ith the car- 
bonate of lime in the soil, is at once converted into neu- 
tral phosphate of lime, which requires to meet with 
another solvent at the place of formation to effect its 
diffusion through the soil, whilst phosphate of ammonia 
spreads through a lime soil just as if there was no car- 
bonate of lime in it. The phosphate of ammonia formed 
when guano is moistened with water (PO, + 3NH,0), 
loses in the air one-third of the ammonia. It is owing 
to this circumstance that guano, when quite dry, will 
keep without alteration ; whereas, when it has been 
fraudulently moistened, to increase the weight, it loses, 
by keeping, considerably in ammonia. 

If guano, just before its application on the field, is 
moistened with water and a little sulphuric acid, suf- 
ficient to give the water a slightly acid reaction, the 
decomposition now mentioned, which otherwise requires 
days and weeks, is effected in a few hours. 



ADDITION OF GUANO TO FAHM-YARD MANURE, 249 

That miano sliould not produce much effect in very- 
dry weatlier needs no explanation, because, without 
water, no substance will act in the ground ; that it 
should, however, equally fail in very wet weather, is, 
undoubtedly, owing in part to the fact that the oxalic 
acid is washed out, as an amnioniacal salt, by the rain 
water, and that there is, accordingly, a corresponding 
quantity of phosphoric acid not made soluble. By the 
above simple and cheap means the injurious influence 
of wet weather upon guano may be completely guarded 
against, inasmuch as the water and sulphuric acid en- 
sure the conversion into a soluble form of the whole of 
the phosphoric acid, which could have been brought in 
to that condition by the oxalic acid. 

The rapidity with which a nutritive substance em- 
ployed in the shape of manure produces an efi'ect, de- 
pends essentially upon the speed with which it spreads 
through the soil, and this, again, upon its solubility ; 
hence it is easy to understand why guano surpasses, in 
these respects, many other manures. 

As regards certainty of action, guano will not bear 
comparison with farm-yard manure, which, from its 
nature, is effective in all cases ; for farm-yard manure 
restores to the land all the soil constituents of the pre- 
ceding rotations, though not in the same proportions, 
whereas guano restores only some of them, and cannot, 
therefore, replace farm-yard manure. As guano, how- 
ever, contains, with the exception of a certain quantity 
of potash, the chief constituents (phosphoric acid and 
ammonia) of the exported corn and flesh, the addition 
of a certain proportion of guano to farm-yard manure 
may serve to restore the proper composition of the lat- 
ter, and, with it, also that of the soil. 

Let us suppose, for the purpose of illustration, that 
a hectare of hind has been manured with S(>0 cwt. of 
firm-yard manure, containing, according to A'oelker's 
aiuilysis, 272 kilogrammes of phosi)liate, and that the 
field has, at the end of the rotation, returned the same 
quantity of fsirui-yard manure of the same composition, 
and has lost by the corn and the animal produce export- 



250 GFANO. 

ed, altogether 135 kilofflramrnes of pliosphates ; the pro- 
ductive power of tliis held, in so far as it depends upon 
the phosphates, would not only remain unaltered, but 
would even be considerably increased, by adding to the 
800 cwt. of farm-yard manure supplied to it at the com- 
mencement of a fresh rotation, 400 lbs. of guano (with 
34 -per cent, of phosphates in it). 

Kilogrammes. 
The farm-yard manure supplied to the land . . 272 of phosphates. 
In the produce exported the field lost . . . 135 " 

There remained in the arable soil .... IZl " 
In the new rotation was added by the fresh supply of 

800 cwt. of farm-yard manure . . . 272 " . 

By the addition of the 400 lbs. of guano . . . 135 " 

Altogether . .' 644 " 

At the beginning of the new rotation the arable soil 
contained, accordingly, twice as much phosphates as at 
the beginning of the preceding one. 

It will thus be seen that, under these circumstances, 
where a held receives back, in the farm-yard manure, a 
larger share of phosphate than it has lost in the crops, 
the action of guano upon it will grow feebler from year 
to year, until at last it ceases to be appreciable. 

But the case is very different as regards the applica- 
tion of guano on fields to which a smaller quantity of 
phosphates is returned in the farm-yard manure than 
has been lost in the crops, and that have, for instance, 
been cultivated for half a century upon the farm-yard 
manuring system. It has already been explained, that 
on such fields certain constituents of the fodder plants 
and of straw, more particularly soluble silicic acid and 
potash, are continually increasing in the arable soil, 
whilst by the export of corn and flesh its store of min- 
eral substances is reduced by the quantity contained in 
the exported matters. The two sets of ct)nstituents had 
jointly produced the crop. By taking away the seed- 
constituents a corresponding amount of the straw and 
fodder constituents was, accordingly, rendered ineffec- 
tive. In fields of this description, manuring with guano 
not only brings up the amount of produce to the former 
standard, but frequently even increases it to a surprising 



KEASON OF THE EFFECTIVE ACTION OF GUANO. 251 

extent, wlicn the soil contains a large store of other as- 
similable food elements, which require only the presence 
of the guano constituents to make them aYailal)lc for 
nutrition. In the increased produce thus obtained, 
there is, of course, carried off, together with the guano 
constituents, also a part of the store of the other food 
elements ; and upon repeated manurings with guano 
thic fertilising effect of tliat agent must therefore neces- 
sarily become feebler in the same proportion as the 
quantity of these other food elements decreases in the 
ground. The fertilising action of all compound ma- 
nures is rarely dependent wpon one constituent alone ; 
and as guano contains, in its ammonia and phosphoric 
acid, two food elements, which require the presence of 
each other to be avaihible, manuring with guano insures 
the action of the phosphoric acid, because the particles 
of the latter are in immediate contact with ammonia 
particles, that are at the same time also available to the 
roots ; and in the same way the phosphoric acid insures 
and increases the action of the ammonia. 

In a soil abounding in ammonia, manuring with 
phosphates alone possessing the same degree of solubil- 
ity. Mill produce the same effect as guano. 

When ammonia salts fail to produce any effect on a 
field whilst guano is found to act favourably, there is 
reason to attribute the beneficial effect of the guano 
principally to the phosphoric acid in it ; but in the 
reverse case the conclusion would not hold equally 
good, because the salts of ammonia produce two dif- 
ferent kinds of effects ; they nuiy, under certain circum- 
stances, considerably increase the amount of produce, 
and yet the favourable effect may not be positively at- 
tributed to the action of ammonia as such (see page 86). 

Tlie presence in the soil of a sufficient quantity of 
potash and silicic acid is always presupposed when 
guano increases the produce of corn ; and on a soil rich 
in potash and magnesia, the a])plication of guano alone 
insures a succession of crops of such plants, which, like 
potatoes, require for their growth chiefl}' potash and 
magnesia. 

Meadows and r-orn fiflH? •which jrave nt first lariic 



252 GUANO. 

crops with guano, becoino at last, by the continued use 
of this agent, frequently so drained of silicic acid and 
potash, as to lose tor many years their original produc- 
tiveness. At the same time it cannot be denied that 
there may be many soils which, for several years, by 
the aid of guano alone, might be made to produce higli 
cereal crops before this state of exhaustion appears ; but 
it will at last inevitably come, and it will then be very 
difficult to repair the damage. 

In 800 cwt. of farm-yard manure with which a hec- 
tare of land is manured in a rotation of crops, the soil 
receives (according to Voelker's analysis) the same 
(piantity of phosphates and of nitrogen as in 800 kilo- 
grammes (15'7 cwt.) of guano ; in other words, there is 
as much of these two elements of food for plants con- 
tained in 1 lb. of the latter agent as in 50 lbs. of farm- 
yard manure. Guano, therefore, contains these ele- 
ments in the most concentrated form, and permits the 
application of them to certain parts of the field more 
conveniently than by farm-yard manure, as is often ad- 
vantageously done after putting in the seed. In many 
places, guano is mixed with gypsum to reduce its over- 
powerfid action. The gypsum divides the guano par- 
ticles and causes them to be more equally distributed 
over the field ; but there is no real diminution of the 
chemical action of the ammoniacal salts ; the gypsum 
decomposes the oxalate and the phosphate of ammonia 
mto sul])hate of ammonia and phosphate and oxalate of 
lime. The phosphate of lime formed in this way is in 
a state of infinitely fine division, in which it is most 
suitable for the roots of plants ; however, a small por- 
tion only of the phosphoric acid is converted into this 
state, and with the removal of the oxalic acid, ceases, 
also, the beneficial influence which the latter exercises 
in promoting the difi'usion of the phosphoric acid. 

It will, therefore, be found much more efiective to 
moisten the guano with water to which a little sulphuric 
acid has been added, and to mix it, after twent)'-fonr 
hours, with saw-dust, turf-dust, or mould, instead of 
gypsum, and to strew this mixture over the surface of 
the field. The rain water dissolves out the phospliat 



GUANO AND SULPHURIC AGIO. 



253 



of ammonia, which slowly sinks into the ground, and 
all parts of the soil with which the sohitiun comes in 
contact are enriched at the same time with phosphoric 
acid and ammonia. If to the saw-dust, turf-dust, etc., 
gypsum is added, it decomposes with the phosphate of 
aunnonia into very finely-divided jjliosphate of lime and 
sulphate of ammonia, which are separated by the rain 
water ; the soluble sulphate of ammonia penetrating 
deeper into the ground and carrying down with it a 
small quantity of the phos})hate of lime, whilst the main 
bulk of the latter is left on the top. 

On land poor in potash, the addition of "U'ood ashes 
to the guano, moistened with water and sulphuric acid, 
will be found beneficial, as the carbonate of potash de- 
composes with the phosphate of ammonia into carbonate 
of ammonia and phosphate of potash, and the potash 
does not interfere with the phosphoric acid penetrating 
into the soil. 

The results obtained, in the Saxon experiments, by 
manuring with guano, afibrd a clear insight into all the pe- 
culiarities observed in the action of this manuring agent. 

If we compare the produce severally obtained by 
manuring with guano and with farm-yard manure (see 
page 186), we are led to the following considerations on 
the condition of the experimental field : — 

Manvring with guano. 





Cunnersdorf. 


Mauscgast. 


Kutiti. 


Oberbobritzsoh. 


Quantity of guano ) 
applied j 

1851. 
Rye corn 


lbs. 

379 

1941 
5979 

17904 

2041 
2873 

9280 


lbs. 

411 

2693 
5951 

17821 

1740 
2223 

0146 


lbs. 
411 

1605 
4745 

19040 

1188 
902 

1250 


lbs. 
616 

2391 


" straw 


5877 


1852. 
Potatoes 

1853. 
Oat corn 


13730 
1792 


" straw 


2251 


1854. 
Clover 


5044 







254 



GUANO. 



Increase of produce above the u?wia7iii7'ed plot (see p. 186). 



Amount of nitrogen |^ 
in the manure . . . . j 

Rye corn 

" straw 

Potatoes 

Oat corn 

" straw 

Red clover 



Cunneisdorf. 



lbs. 
49-3 

765 
£028 

1237 

22 
310 

13G 



Mausegast. 

(1353, barley 

iusload of oats.) 



lbs. 
53-4 

4.55 
13(59 

925 

451 
383 

608 



lbs. 
63-4 

S41 

1732 

463 

151 

455 

161 



Obeibobiitzsch. 



lbs. 
80-1 

938 

2862 

3979 

264 
439 

4133 



In Ciinnersdorf, the increase of prodnce obtained 
in 1851, over the unmaiiured field, amounted to — 



By farm-yard manure (180 cwt.) . 
By guano (379 lbs.) 



Corn. Straw. Ratio, 
lbs. lbs. lbs. 

337 1745 =1:5 

765 3028 = 1 : 3-i 



The field at Cunnersdorf was naturally rich in those 
ingredients which we have designated as 8f (straw) con- 
stituents (silicic acid, potash, lime, magnesia, iron), and 
the increase of these by the farm-yard manure aug- 
mented the straw at the expense of the grain crop. 
The farm-yard manure contained too little of the K 
(corn) constituents (nitrogen, pliosphoric acid). 

This explains the powerful action of guano (which 
contains cliiefly K constituents) upon this field ; the 
increase of corn by its means was more than double 
that obtained from farm-yard manure, and a more suit- 
able proportion was established between the K and S^ 
constituents in the ground. 

At Mdusegast the increase of produce obtained in 
1851, above that of the unmanured field, amounted to — 

Corn. Straw. Ratio, 

lbs. lbs. lbs. 

By farm-yard manure (194 cwt.) ... 345 736 = 1 : 2-1 

By guano (411 lbs.) 455 1369 = 1 : 3'0 

This field was richer in K and Si constituents than the 



EFFECT OF GUANO ON 6TKAW PRODUCE. 255 

Cimnersdorf field, and contained, already, an excess of 
S^ constituents. The K constituents supplied in the 
guano constituted a much smaller fraction of the -whole 
store already present in the field than was the ease 
•with the Cunnersdorf field, and their effect tended 
rather to increase the produce of straw than tliat of 
corn. 

Tlie application of guano had the effect of producing 
the same quantity of straw on the Cunnersdorf as on 
the Miiusegast field (5951 and 5979 lbs.); but the corn 
reaped from the latter exceeded that obtained from the 
former by T52 lbs. The Mausegast field was much 
richer in K constituents than the Cunnersdorf field. 

At Kotitz the increase of produce was — 

Corn. Straw. Eatio. 
11)S. lbs. lbs. 

Bv farm-vard manure (229 cwt.) . . . 352 lOOG = 1 : 2-8 

By guano (411 lbs.) 341 1732 = 1:5 

The effect of guano upon the straw produce was here 
out of all proportion greater tlian that of farm-yard 
manure, whilst the produce of corn was smaller. It is 
quite evident that one constituent acting more power- 
fully in the direction of the formation of straw was 
supplied to the field in larger proportion in the guano 
than in the ftirm-yard manure. Experiments with 
superphosphate (excluding ammonia), or with an am- 
moniacal salt (excluding phosphoric acid), would have 
shown to which of these two elements the dift'erence in 
the produce was owing. 

At ObcrJjohritzsch the increase of produce was — 

Corn. Straw. Ratio, 

lbs. lbs. lbs. 

By farm-yard manure (314 cwt.) . . . 452 913 = 1:2 

By guano (616 lbs.) 938 2812 = 1:3 

As the quantity of guano used at Oberbobritzsch Avas 
about 50 per cent, more than in the preceding experi- 
ments, no com])arison as to amount can be made 
between the produce of this field and that of the others. 
What is again remarkable here is the similarity of the 
condition of this and the Mausegast field ; on both, 



256 



GTJANO. 



farm-yard manure gave straw and corn in tlie propor- 
tion of 1'2; guano, in the proportion of 1'3. As 
regards the power of the sohible guano constituents to 
pass through the soil, we find from these experiments 
the same conditions existing as with those of farm-yard 
manure. At Cunnersdorf and Kotitz the whole guano 
constituents hardly produced any efiect upon the clover 
crop ; whilst at Miiusegast and Oberbobritzsch a per- 
ceptible increase was the result. 

Silicic acid, which gives strength and firmness to 
stalks and leaves, is not one of the ingredients of guano ; 
hence, after manuring with guano, the tendency of the 
cereals to lodge, so much dreaded by agriculturists, is 
observed on many fields poor in silicic acid, whilst on 
others abounding in this substance it does not occur. 
On many soils this tendency may be cured by dressing 
with lime before applying the guano ; and in other 
cases it may be lessened by mixing dung made from 
straw with the guano. 

If we calculate the increase in the produce of 
cereals, potatoes, and clover, obtained severally in the 
years 1851 to 1854, from 100 lbs, of guano we find 

100 lbs, of guano gave increase of produce. 



1851 and 1853. 
Rye and oats 

1852. 
Potatoes 

1854. 
Clover 



Cunnersdorf. 


Mausegast. 


Kutitz. 


lb. 


lbs. 


lbs. 


1088 


646 


354 


326 


225 


112 


36 


172 


39 



Oberbobritzsch. 



lbs. 
V31 

646 

670 



These results show that the same quantity of guano 
has an equally dissimilar eff*ect upon difierent fields as 
farm-yard manure, and that it is quite impossible to 
draw from the crops obtained any inference as to the 
quality or quantity of the manuring agent employed to 
produce them. The field at Mausegast had received 



INCREASE OF PKODUCE BY GUANO. 257 

the same amount of guano as the Kotitz field, both, 
accordingly, the same quantity of nitrogen and phos- 
phoric acid ; 3^ct in cereals and potatoes the increase of 
produce was twice as great, and in clover much greater 
in the former tlian in the latter. 

How very little the crops will enable us to draw 
comparisons between the effects of the several constitu- 
ents of one and the same manuring agent, may be 
clearly seen from the results of the experiments at 
Cunnersdorf and Oberbobritzsch. 

At Cunnersdorf, 100 lbs. of guano gave an increase 
of produce in cereals, potatoes, and clover, containing — 

Phosphoric 
Nitrogen. Potash. acid. Lime, 
lbs. lbs. lbs. lbs. 

Increase of produce .. . 0-2 IC'l 85 3-6 
The guano contained . . 130 2-0 12-0 12-0 

More in the manure . . 3"S — 8'5 8"4 less in the crops. 

Less in the manure ... — 141 — — more in the crops. 

At Oberbobritzsch, 100 lbs. of guano gave an increase 
of produce, containing — 



Increase of produce . 
The guano contained 

More in the manure . 
Less in the manure . 

The difference in the effect produced by the guano 
on the two fields is most strikingly exhibited by these 
tables. At Cunnersdorf the produce reaped contained 
30 ])er cent, less, at Oberbobritzsch 77 per cent, more 
nitrogen than the manure applied. 



Nitrogen, 
lbs. 


Potash. 

lbs. 


Phosphoric 

acid. Lime, 
lbs. lbs. 


, 23-0 
13-0 


15-5 
2-0 


6-1 
120 


lG-9 
120 


. 10-U 


13-5 


5-0 


— less in the crops. 
4-9 more in the crops. 



CHAPTER VII. 

POTJDEETTE HUMAN EXCKEMENTS. 

Poudrette, nature of ; small amount of the food of plants in it— Iliiman excrement 
its value— Construction of the privies in the barracks at Rastadt — Calculation 
of the amount of corn produced by the excrement collected ; importance to the 
neighbourhood— Its effect not impaired by deodorising with sulphate of iron — 
The excrement of the inhabitants of towns as manure— Its importance. 

POUDRETTE, sold as manure, should consist simply 
of the desiccated excrements of man made into a 
transportable form. This is not the case, however, as 
most poudrettes contain, in reality, only a comparative- 
ly small proportion of excrementitious matter. To 
show this, it will suffice to point out that the poudrette 
of Montfaucou, which is one of the best sorts, contains 
28 per cent., that of Dresden from 43 to 56 per cent., 
that of Frankfort above 50 per cent,, of sand. No kind 
of poudrette is ever met with in commerce containing 
more than 3 per cent, of phosphoric acid, and the same 
amount of ammonia. The construction of j^rivies in 
dwelling-houses (at least, in Germany) does not make 
it practicable to keep out the sweepings and other rub- 
bish of the house ; besides, when emptying the pits, it 
is often the practice, after taking out the fluid contents, 
to throw into the residuary mass some solid porous 
body, such as brown-coal or turf-dust, to make it drier 
and more convenient for removal. All additions of the 
kind, of course, diminish the percentage of efiective and 
available food elements, and increase the costs of trans- 
port. The privy pits, moreover, are but rarely water- 
tight, and permit the greater part of the urine and 



VALUE OF HUMAN EXCREMENTS. 259 

other fluid contents to leak away, thus causing the loss 
of a g;ood deal of the most valuable matter, such as the 
potash salts, and the soluble phosphates. The follow- 
ing statement will show the great value of the excre- 
ment of man. In the fortress of Rastadt and in the 
soldiers' barracks in Baden generally, the privies are so 
constructed that the seats open, through wide funnels, 
into casks fixed upon carts. By this means the whole 
of the excrements, both fluid and solid, are collected 
without the least loss. When the casks are full, they 
are replaced by empty ones.* 

The food of the soldier, in Baden, consists chiefly of 
bread, but also of certain daily rations of meat and 
vegetables. As the body of an adult does not increase 
in weight, it needs no particular calculation to make 
out that the collected excrements must contain the ash- 
constituents of th.e bread, meat, and vegetables, and 
also the whole of the nitrogen of the food. 

To produce a pound of corn, the soil has to furnish 
the ash-constituents of that pound of corn ; if we sup- 
ply these ash-constituents to a suitable field, the latter 
will thereby be enabled to produce, in a number of 
years, one pound of corn more than it Avould have done 
without this additional sujiply of ash-constituents. The 
daily ration of a soldier, in Baden, is 2 lbs. of bread; 
the excrements of the 8000 men of the different garri- 
sons contain accordingly, per day, the ash-constitucnts 
and the nitrogen of 16,000 lbs. of 15read, which returned 
to the soil will fully sutfice to reproduce the same quan- 
tity of corn as had been used, in form of flour, to bake 

* The price of a cart is from 100 to 125 florins = £8 fis. Bd. to £10 S.s. 
4d. It will last about five years. The original outlay incurred by the 
Army administration in Baden, in 1856 and 1857, for the carts and casks 
amounting to about £370, was speedily repaid out of the proceeds of the 
manure. 

The collective number of the f^arrisons of Constance, Freiburg, Rastadt, 
Carlsruhe, Bruchsal, and Mannheim, averages about 8000 men. The 
receipts for manure sold were in 1852, £285; in 1853, £315; in 1854, 
£443 ; 1855, £400 ; 1856, £Go8 ; 1857, £608 ; 1858, £680 ; £50 or £60 
arc to be deducted from these receipts annually for cost of maintenance, 
repair, Ac, of the carts, &c. (' Journ. of the Agric. Soc. of Bavaria,' April 
1800. Page 180.) 



260 POUDKETTE — ^HUMAN EXCREMENTS. 

the 16,000 lbs. of bread. Reckoning 1^ lb. of corn to 
2 lbs. of bread, tlie excrements of the soldiers in the 
Grand Duchy of Baden give, therefore, annually, the 
ash-constituents required for the production of 43,760 
cwts. of corn. 

The peasants about Rastadt and the other garrison 
towns, having found out at last by experience the pow- 
erful fertilising effect of these excrements upon their 
fields, now pay for every full cask a certain sum (still 
rising in price every year), which not only has long 
since repaid the original outlay, besides covering the 
annual cost of maintenance, repairs, &c., but actually 
leaves a handsome profit to the department. 

The results brought about in these districts are 
highly interesting. Sandy wastes, more particularly in 
the vicinity of Rastadt and Carlsruhe, have been turned 
into smiling corn-fields of great fertility. Assuming, 
for the sake of illustration, that the peasants had to fur- 
nish the whole com produced by means of this manure, 
to the military administrations of the several garrison 
towns, there would thus be established a perfect circu- 
lation of these conditions of life, which would provide 
8000 men with bread, year after year, without in the 
least reducing the productiveness of the fields on which 
the corn is grown, because the conditions required for 
the production of corn being thus always returned to 
the soil, would continue to circulate and yet always re- 
main the same.* 

What is said here about the corn-constituents ap- 
plies, of course, equally to the constituents of meat and 
vegetables, Avhich, returned to the field, will reproduce 
as much meat and vegetable matter as has been con- 
sumed. The same relation that exists between the in- 

* When, some years ajro, an order was suddenly issued by the authori- 
ties of the city of Carlsruhe, to deodorise and disinfect the pits and cess- 
pools with sulphate of iron, before being emptied, the farmers refused at 
first to pay any longer for the contents, which they argued were by this 
treatment deprived of their fertilising virtue. Experience has shown that 
this is not the case, and the disinfected dung commands as high a price 
now as the article in its pure state did formerly. The dung in the privy 
carts requires no disinfecting. 



LOSS OF MANURE BY CAKELESSNESS. 201 

habitants of the barracks in Baden and the fields sup- 
plying them with bread, exists ecpially between the in- 
habitants of towns and tlie country around. If it were 
practicable to collect, witliout the least loss, all the solid 
and fluid excrements of all the inhabitants of towns, and 
to return to each farmer the portion arising from the 
produce originally supplied by him to the town, the 
productiveness of his land might be maintained almost 
unimi)aired for ages to come, and the existing store of 
mineral elements in every fertile field would be amply 
sufficient for the wants of the increasing populations. 
At any rate, that store is, at present, still sufficient to 
do so, although the number of farmers who take care 
to cover by an adequate supply of suitable manures the 
loss of minora! matters sustained by the land in the crops 
grown on it, is but small in proportion to the whole 
agricultural population. However, sooner or later, the 
time will come when the deficiency in the store of these 
mineral matters will be important enough in the eyes 
of those who are, at present, so void of sense as to be- 
lieve that the great natural law of restoration does not 
apply to their own fields ; and the sins of the fathers, 
in this respect, will also be visited upon their posterity. 
In matters of this kind, inveterate evil habits are but 
too apt to obscure our better judgment. Even the most 
ignorant peasant is quite aware that the rain falling 
upon his dung-heap washes away a great many silver 
dollars, and that it would be much more profitable to 
him to have on his fields what now poisons the air of 
his house and the streets of his village ; but he looks 
on unconcerned, and leaves matters to take their course, 
because they have always gone on in the same way. 



CHAPTEE YIII. 

EARTHY PHOSPHATES. 

High agricultural value of phosphates — Phosphates of commerce ; selection of the 
kind to be used dependent on tlie object in view, and on the nature of the Boil— 
The riipidit}^ and duration of the eftVct of the neutral and of the soluble phos- 
phate (superphoBphate) of lime — The Saxon manuring experiments. 

THE earthy phosphates are among the most impor- 
tant agents for restoring the impaired productive- 
ness of land ; not that they influence vegetation in a 
more marked manner than other mineral elements, but 
because the system of cultivation pursued by the corn 
and flesh producing farmer tends to remove them from 
the soil in larger proportion than other constituents. 

In choosing among the phosphates of commerce, 
the farmer should always keep in view the object which 
he intends to accomplish, as some sorts will answer 
better for certain purposes than others. 

The so-called superphosphates are commonly phos- 
phates to which a certain quantity of sulphuric acid 
has been added, to convert the insoluble neutral lime 
salt into a soluble acid salt. ^Vlien mixed with a salt 
of ammonia and a salt of potash, they are often called 
guano or ammoniacal superphosphates. A good super- 
phosphate generally contains from 10 to 12 per cent, 
of soluble phosphoric acid. On land poor in clay and 
lime the superphosphates are particularly suitable for 
supplying the upper layer of the soil with phosphoric 
acid. Their effect upon the produce of potatoes and 
of cereals on such fields is equal to that of Peruvian 
guano. For turnips and rape, which derive advantage 



PKOPERTIES OF BONE-DUST. 2G3 

from the presence of sulphuric acitl, they have a special 
value. On chalky soils, the free phosphoric and sul- 
phuric acids are immediately neutralised, by which they 
are deprived of one of thcnr essential properties, viz., 
their ready diffusibility, which renders them so valuable 
a manure for other soils. 

Among the neutral phosphates bone-dust holds the 
first rank. When bones are exposed, under high pres- 
sure, to the action of steam, they lose their toughness, 
and swell up into a soft gelatinous mass, which, after 
drying, may be readily ground to a fine powder. In 
this lorm it spreads, with great rapidity, through the 
soil ; it dissolves in water to a small but perceptible 
extent, without requiring the presence of any other 
solvent. AVhat dissolves, under these circumstances, 
in water, is a combination of gelatine with phosphate 
of lime, which is not decomposed by the arable earth, 
and therefore penetrates deej) into the ground — a prop- 
erty wanting in the superphosphate. In the moist 
ground, however, the gelatine speedily putrefies, being 
converted into ammonia compounds, and the phosphate 
of lime is then retained by the arable earth. Bone-dust 
is the agent best adapted to supply phosphate of lime 
to the deeper layers of the arable soil, for which pur- 
pose the superphosphates are not suitable. Bone-earth, 
or bone-ash, is the name applied to bones freed, by cal- 
cination, from the glue or gelatinous part. The animal 
charcoal of sugar refineries belongs to this category. 
It must be reduced to the finest powder to render it 
fully available for manuring pur]3oses. To efi'ect its 
more speedy distribution through the soil, the presence 
of a decaying organic substance is necessary to supply 
the carbonic acid required for its solution in rain water. 
An excellent way is to mix the powder with fjirm-yard 
manure and let the mixture ferment. Among the phos- 
phates of commerce, the guano coming from the Baker 
and Jarvis Islands are distinguished, before others, by 
their acid reaction and greater solubility. They con- 
tain only a small quantity of an azotised substance, no 
uric acid, and small proportions of nitric acid, potash, 

A: 



264: 



EARTHY PHOSPHATES. 



magneisa, and ammonia. The Baker gnano contains 
as niiieh as 80 per cent., the Jarvis guano 33 or 34 per 
cent, of phosphate of lime ; the hitter having, besides, 
44 per cent, of gj^sum. In diffusibility, tliese guanos, 
when equally finely powdered, approach nearest to bone- 
dust : their condition also enables the farmer who wishes 
to accelerate their action, to convert them most readily 
into superphosphates (100 parts by weight of Baker 
guano require 20 to 25 per cent, of concentrated, or 30 
to 40 per cent, of the lead chamber sulphuric acid). 

The influence of these neutral phosphates upon the 
produce of a field is generally less marked in the first 
than in the following years, as it takes a certain time 
to efiect their diflusion through the soil. The speedier 
or slower manifestation of their action upon a field 
depends, in a great measure, upon the state of fine- 
ness of the powder, to which they have been reduced, 
the greater or less porosity of the soil, the presence in 
it of decaying matters, and careful tillage ; but, under 
any circumstances, they require a certain store of sol- 
uble silicic acid, and of soda and potash in the soil. 

The subjoined table giving the produce obtained, 
in the years 1847-50, by H. Zenker, at Kleinwolmsdorf, 
in Saxony, shows the difierence between guano and 
bone-dust as regards rapidity and duration of action. 
In the first year the guano gave the larger produce, 
which became smaller in each following year ; in the 
first year the crop from the bone-dust was smaller, but in 
the succeeding years the increase was most remarkable. 





Bone-dust (822 lbs.). 


Guano (411 lbs.). 




Corn. 


Straw. 


Corn. 


Straw. 


1847. 
Winter corn 


lbs. 
2798 

2862 

1591 

1351 


lbs. 
4831 

3510 

5697 

2768 


lbs. 
2951 

2484 

1095 

732 


lbs. 
4711 


1848. 
Barley 


8201 


1849. 
Vetches 

1850. 
Winter corn 


4450 
2481 







PEODUCE FKOM GUANO AND BONE-DUST. 



26; 



The 411 lbs. guano contained 53, and the total pro- 
duce 271 lbs. of nitrogen, or very nearly five times 
more. The bone-dust contained 37 lbs. of nitrogen, 
whereas in the total produce there were 342 lbs., or 
nearly nine times more. The bone-dust gave in the 
crops altogether 71 lbs. of nitrogen more than the guano. 
Between the quantity of nitrogen in the manure and 
the amount of the crops reaped, there is, therefore, no 
connection Mhatever. 

In the Saxon experiments, the plots manured with 
bone-dust gave the following results : — 
Manuring with hone-dust. 





Cunnersdorf. 


Kotilz. 


Oberbobritzsch. 


Mausegast. 


Quantity of bone-dust) 
used ) 

1851. 
Rye corn 


lbs. 
823 

1399 
41G7 

18250 

2346 
3105 

10393 


lbs. 
1233 

1429 
3707 

19511 

1108 
1224 

2186 


lbs. 
1644 

2230 
5036 

11488 

1718 
1969 

7145 


lbs. 
892 

1982 


" straw 


4365 


1852. 
Potatoes 


19483 


1853. 
Oat corn 


1405 


" straw 


1905 


1834. 
Clover 


5639 







Inxireme of produce over the unmanured field (see p 


. 186). 




Cunnersdorf, 


Kotitz. 


Oberbobritzsch. 


Mausega.st. 
(1833, l).arleT 
instead of uau.) 


1851. 
Rye corn 


lbs. 

227 
1216 

1583 

327 


lbs. 

165 
694 

934 


lbs. 

777 
2021 

1737 

100 
157 

6234 


lbs. 


" straw 

1852. 
Potatoes 


2587 


1853. 
Oat corn 


110 


" straw 


542 — 
1249 n>'.)i 


65 


1854. 
Clover 


101 











12 



266 



EAETHY PHOSPHATES. 



The field at Kotitz got 60 per cent, more bone-dust 
than the Cunnersdorf field ; yet its produce of all the 
crops was lower than that of the latter. The field at 
Oberbobritzsch got, in 1851, twice the quantity of 
manure that was applied to the Cunnersdorf field ; the 
result was, in the first year, an increase of corn of 250 
per cent., and of straw of 66 per cent, more on the for- 
mer than on the latter. In the third year, however, 
the increase of produce of oats, both in grain and straw, 
was considerably larger at Cunnersdorf than at Ober- 
bobritzsch. 

The most curious part of the results is the great 
difierence in the increase of the produce of clover on 
the several fields ; from the field at Oberbobritzsch 
nearly six times as much clover was obtained as irom 
that at Ivotitz, although the former had received only 
one-fourth more bone-dust than the latter. 

A glance at the table shows that in the experiments 
at Cunnersdorf, Kotitz, and Oberbobritzsch, the quan- 
tities of bone-dust severally applied as manure were as 
1 : 1|^ : 2. A comparison of the increase of produce 
obtained by bone-earth, just as in the case of guano 
and farm-yard manure, again demonstrates that there 
is no connection or relation of dependence between the 
amount of manure and the increase of the crops. 



100 lbs. lone-dust gave increase ofproduce- 


— 




Cunnersdorf. 


Kotitz. 


Oberbobritzsch. 


1851 and 1853. 
Rye and oats 


lbs. 
280-8 

192 

152 


• lbs. 
40-1 

75 

96 


lbs. 
191 


1852. 
Potatoes 


105 


1854. 
Clover 


380 







CHAPTER IX. 

GKOUND RAPE-CAKE. 

Nature and composition of , the diffusibility of its constituents in the soil is com- 
paratively great— Its importance as a manuring agent is small— The Saxon 
agricultural experiments with rape-cake— The inforeuces from them. 

THE residuary ina-s left by rape-seed after the extrac- 
tion of the fatty oil from it by the press, contains a 
large proportion of a matter abounding in nitrogen, 
which is nearly related to the casein in milk. In addi- 
tion to this substance, it contains the same incombusti- 
ble or ash-constituents as the ashes of seeds. The rape- 
seed ash consists of phosphates, and differs but little in 
composition from the ash of the grain of rye ; phos- 
phates of the alkalies and phosphates of magnesia pre- 
dominate in it. There is no great error made in assum- 
ing that in 100 lbs. of rape-cake a field receives the same 
amount of the incombustible constituents of rye grain 
as is contained in 250 to 300 lbs. of the latter. 

The azotised matter in rape-cake powder is slightly 
soluble in water, but its solubility increases with inci- 
pient putrefaction ; hence the nutritive matters con- 
tained in it are much more widely diffused in the ground 
than, for instance, the principal ingredients of guano, 
ammonia, and phosphoric acid, which are absorbed, as 
soon as dissolved, by the earth particles that come in 
contact with them. Whereas with rape-cake powder 
this takes place only after its azotised matter has been 
completely decomposed, and its nitrogen converted 
into ammonia. This decomposition proceeds, however, 



268 



GROUND EAPE-CAKE. 



pretty fast, and the efiect of rape-cake makes itself felt, 
accordingly, in the very iirst year of its application. 

It is owing to this greater diifusibility of its con- 
stituents in the earth that rape-cake appears to exer- 
cise a somewhat more powerful effect upon vegetation 
than guano, for instance, with an equal amount of phos- 
phoric acid. 

However, rape-cake holds no very important rank 
as a manure, simply because very few agriculturists 
are in a position to procure any considerable quantity 
of it for manuring purposes. Besides, when its great 
value as an article of food for cattle shall be more uni- 
versally known and acknowledged, the increasing price 
"will restrict, still more, its use as a manuring agent ; 
tlie more so since the excrements of animals fed upon 
rape-cake contain the principal bulk of the constituents 
to which is due its efiicacy as a fertilising agent. 

The following results were obtained, in the Saxon 
exj)eriments, by manuring -with ground rape-cake : — 





Cunnersdorf. 


Mausegast. 


Kutitz. 


Obeibobritziich. 


Manure 


lbs. 
1614 

1868 
5699 

17374 

2052 
2768 

9143 


lbs. 
1855 

2645 
5998 

18997 

b.arley 
1619 
2298 

6659 


lbs. 
1849 

1578 
4218 

19165 

1408 
1550 

981 


lbs. 

3288 


1851. 
Rye corn 


1946 


" straw 


4475 


1852. 
Potatoes 


10442 


1853. 
Oat corn 


1517 


" straw 

1854. 
Clover 


1939 
2105 







KAPE-CAKE AS A iMANURE. 269 

Increase of produce over the tinmanured field (see p. 186). 





Cunnersdorf. 


Mausegast. 


Kotitz. 


Obeibobtltzsch. 


Amount of nitrogen ) 
in manure ) 

1S51. 

Rye corn 

" straw 


lbs. 
78-9 

692 
2748 

707 

33 

205 


lbs. 
88-8 

407 
1416 

2101 

330 
458 

1121 


lbs. 
89 

314 

1205 

588 

69 
193 


lbs. 
157-8 

493 
1460 


1852. 
Potatoes 


691 


1853. 
Oat corn 




" straw 


127 


1854. 
Clover-liav 


1194 







Here, again, we see, as in the case of farm-yard 
manure, guano, and bone-dust, that on no one field did 
the effect of the rape-cake bear any visible proportion 
or relation to the quantity used. 

1000 Ihs. of ground rape-calce gave increase of produce — 





Cunnersdorf. 


Mausegast. 


Kctitz. 


Oberbobrltzsch. 


1851. 
Rye corn and straw . . . 

1853. 
Oat corn and straw 

1852. 
Potatoes 


lbs. 
2130 

147 

438 


lbs. 
989 

424 

1132 

604 


Ibe. 
820 

141 

318 


lbs. 
594 

39 

210 


1854. 
Clover-hay 


332 







These experiments are interesting in reference to 
the effect of the nitrogen supplied in the manure. A 
comparison of the increase of produce obtained at Ober- 
bobritzsch, severally by gxiano and ground rape-cake, 
gives the following result in this respect : — 



270 GEOUOTD KAPE-CAKE. 

Oherbobritzsch. 

611 lbs. pnano 82S3 lbs. ground rape-cako 

= 80 lbs. nitrogen = 167-8 lbs. nitrogen 

and 74 lbs. aud 89-5 lbs. 

phosphoric acid. phosphoric acid. 

1851 and 1853. Rye and oata 4503 lbs. 2069 lbs. 

1852. Potatoes 3979 " G91 " 

1854. Clover-hay 4133 " 1194 " 

The one field at Oberbobritzscli received in tlie ground 
rape-cake nearly double the quantity of nitrogen that 
the other got in the guano, and the difference in the prod- 
uce of the two is in the highest degree striking. 
In the two experiments — 

In the In the 

guano. rape-cake. 

The nitrogen in the manures was as 1 : 2 

In the produce it was : 



cereals, as ... 2 

potatoes, as 5'7 

clover, as 3"4 



The effect of the nitrogen in the guano was, accord- 
ingly, in the cereals four times, in the potatoes twelve 
times, and in the clover seven times, greater than that 
of the nitrogen in the rape-cake. 

Upon comparing the increase of produce with the 
amount of phosphoric acid in the two manures, we find 
that this increase appears to bear some proportion, 
though yet by no means a definite one, to the amount 
of phosphoric acid severally contained in them. 

The general results of the experiments made, in a 
four years' rotation, on four different fields at Cunners- 
dorf, Mausegast, Kotitz, and Oberbobritzscli, may be 
summed up as follows : — 

The 48 harvests from the unmanured plots and from 
those manured severally with bone-dust, guano, and 
ground rape-cake, gave in rye grain and straw, in po- 
tatoes, in oats grain and straw, and in clover, by manur- 
ing with — 



Guano. 

lbs. 
1139 


Ground 
rape-cake, 
lbs. 
1046 


910 


910 


229 


136 


23G 


415 



SUMMARY OF RESULTS. 271 



Bone-dust, 
lbs. 
Total amount of nitrogen in crops. . . 1170 
Total amount of nitrogen in crops ) „,q 
from unmanurcd plots j 

Increase of nitrogen over the un- ) „(■() 

manured plots ) 

The manure contained nitrogen 207 

More than in manure 53 less Y less 2*79 

Tlie manure poorest in nitrogen (the bone-dust) thus 
actually gave the highest, and the one richest in nitro- 
gen (the rape-cake) the lowest, amount of that element 
in the produce. 

To 100 lbs. nitrogen in the manure, there was ob- 
tained of that element in the increased produce — 

By bone-dust 125 lbs. 

" guano 97 " 

" rape-cake 32 " 

Tlic amount of phosphoric acid in the crops was 
from — 

Ground 
Bone-dust. Guano. rape-cake. Unmanured. 
lbs. lbs. lbs. lbs. 

Phosphoric acid 361 362 338 292 

The manure contained 1102 288 86 — 

The fields gained 741 — — — 

The fields lost — 74 252 292 



CHAPTEK X. 

■\VOOD-ASH. 

The amount of the food of plants in it— Box-'n-ood ash gives only the half of its 
potash readily to water- Convenience in mixinit wootlash with earth before 
applying it— Lixiviated ash, its value— Proper mode of applying ashes as a 
manure. 

IT has already been stated that the proportion of pot- 
ash is very dissimilar in difterent wood-ashes ; those 
from hard wood being generally richer in that sub- 
stance than those from soft wood. The ash of beech- 
Avood gives up to water the one-half of the potash in it, 
in the form of carbonate of potash, the other half remain- 
ing in combination with carbonate of lime, in a com- 
pound which is only very slowly decomposed by cold 
water. The ash of pine-wood generally contains, like 
tobacco-ash, a larger proportion of lime, so that cold 
water often seems to fail altogether in dissolving any 
carbonate of potash out of it. However, the continued 
action of water succeeds always in gradually extracting 
from all these ashes the whole of the potash ; and since 
they can be easily ploughed deeply in, they are suited 
better than all other potash compounds to enrich with 
that alkali the deeper layers of the arable soil. With 
wood-ashes that part readily with their potash to water, 
it will be found useful to mix the ash, before applying 
it, with an earth that absorbs potash, adding so much 
of the latter that water poured upon the mixture will 
no longer turn reddened litmus-paper blue. This oper- 
ation of mixing can best be performed on the field itself. 
"Wood-ash which has been extracted with water, 



APPLICATION OF ASHES AS A MANURE, 273 

such, for instance, as the residue left in preparation of 
potash, possesses for many fields a high value as a 
manuring agent, not only on account of the potash 
always present in it, but also of the phosphate of lime 
and soluble silicic acid it contains. 

As the upper layers of our corn-fields contain already 
naturally an excess of potash, in proportion to the other 
food elements, ash-manuring, when confined to the sur- 
face soil, rarely exercises a lasting efi'ect ; but where the 
ash is carried down to the proper depth, it affords an 
excellent means of obtaining permanent crops of clover, 
turnips, or even potatoes. In.telligent manufacturers 
of beetroot sugar use with great success the rcsiduarv 
matter from the distillation of their molasses, which 
contains all the potash-salts of the beetroot, for manur- 
ing their fields, to restore to them the potash removed 
m the beetroot-crops. 

12* 



CHAPTER XI. 

AMMONIA AND NITRIC ACID. 

Source of the nitrogen of plants — Amount of ammonia and nitric acid in rain and 
dew : Bineau, Boussingault, Knop — Quhntity of ammonia in the air — Quantity 
of nitrogenous food brought to the soil yearly by rain and dew ; more present 
in the soil than is removed by the crops — The general reason for decrease of 
productive power in eoils— Classification of manures according to the amount 
of nitrogen ; assimilable and sparingly assimilable nitrogen ; the nitrogen 
theory; only ammonia according to this theory is wanting ; resemblance to 
the humus theory — Manuring experiments with compounds of ammonia by 
Schattenmann, by Lawes and Gilbert, by the Agricultural Union of Munich, 
and by Kuhlmann — The efficacy of a manure is not in proportion to its amount 
of nitrogen : cxperimentB — Large amount of nitrogen in soils ; the experiments 
of Schmid and Pierre ; the arable surface soil contains most nitrogen — Form 
of the ammonia in the soil ; Mayer's experiments — Comportment of soil and 
farm-yard manure with the alkalies— The ineflective nitrogen of the soil made 
effective by the supply of ash-constituents that are wanting— Progress in ag- 
riculture impossible if dependent on a supply of ammoniacal compounds ; re- 
sults of Lawes' expernnen twith snlts of ammonia— The artificial supply of 
ammoniacal manures contrasted with the crops produced and tlie increase of 
population — Increase of nitrogenous food by n;\tural means ; formation of 
nitrite of ammonia by oxidation in the air according to Schonbeim — Supply of 
food in excess necessary to produce corn-crops ; reasons — How the necessary 
excess of nitrogenous food for corn may be obtained from natural sources — The 
supply of nitrogen in farm-yard manure in the Saxon experiments correspond- 
ed to the crop of clover-hay — Loss of nitrogen in lime soils by oxidation ; 
utility of a supply of nitrogen to such soils — Efl'ect of nitrogenous food on the 
aspect of young plants ; on potatoes — Empirical and rational systems of agri- 
culture. 

FROM the results of a series of most careful observa- 
tions extending over a number of years made by 
Bineau in different parts of France on the amount of 
ammonia and nitric acid in rain-water, it appears that 
there fell annually upon the area of a hectare (= 2i 
acres) 27 kilogrammes (= 59 lbs.) of ammonia (= 22 
kilo. = 48 lbs. nitrogen), and 34 kilogrammes (= 75 
lbs.) of nitric acid (= 5 kilo. = 11 lbs. nitrogen) ; alto- 
gether, therefore, 27 kilo, or 54 Zollv. lbs. (= 69 lbs. 
Eng.) of nitrogen. 



AMMONIA CONVEYED IN KAIN AND DEW. 275 

For an Eno^lisli acre tliis makes 21'9 Zollv. lbs. {= 24 
lbs. Eng.), and for a Saxon acre 30 Zollv. lbs. These 
numbers nearly coincide with the observations of Bous- 
singanlt and Knop. 

The yearly average quantity of rain falling in vari- 
ous districts, according to the position and elevation of 
the localities, is very unequal ; and investigations have 
shown that the amount of ammonia and nitric acid con- 
tained in rain-M'ater bears an inverse proportion to the 
quantity of rain. In districts where the rain falls more 
seldom or less in quantity, the water is richer in these 
constituents than in more rainy districts. According 
to Boussingault, dew is richest in ammonia ; according 
to Knop, not richer than rain-water. (See his valuable 
memoir in the 8 hefte der ' Landw. Yersuchstat. in 
Sachsen.') But plants receive ammonia and nitric acid 
not merely by means of rain-water derived from the 
ground and in dew, but also directly from the atmos- 
phere. The experiments of Boussingault (' Annal. de 
Chem. et de Phys.,' 3 ser. t. liii.) leave no doubt what- 
ever with regard to the constant presence of ammonia 
in the air. In a kilogramme of the following sub- 
stances heated to redness, he found these quantities of 
ammonia, after three days' exposure to the air uj)on 
porcelain plates : — 

In 1 kilo, quartz-sand 0'60 milligr. ammonia 

" 1 " bone-ash 0-47 " 

" 1 " charcoal 2'9 " 

Although we can estimate with tolerable certainty 
the quantity of ammonia and nitric acid which a field 
annually receives in rain-water, yet the determination 
of the same in the dew which moistens plants is not 
practicable. Just as little can we discover how much 
ammonia or nitric acid is received by plants directly 
from the air, simultaneously M'ith carbonic acid. 

In the elevated plateaus of Central America, where 
it scarcely ever rains, the cultivated and wild ])lants 
receive their nitrogenous food only from the dew or 
directly, from, the air ; and we .may assume, without 



276 



AMMONIA AND NITEIC ACID. 



risk of error, that the plants which grow in the culti- 
vated fields of Europe have as much ammonia and nitric 
acid furnished to them by the air and the dew, as is con- 
veyed to them in rain-water. A sandy plain, where no 
plants grow, receives from the rain as much ammonia 
and nitric acid as a cultivated field ; but the latter de- 
rives a greater quantity through the plants, and more 
from the leafy plants, than from those which are poor 
in leaves. Let us assume that in the Saxon experi- 
ments the cereal plants, potatoes, and clover, raised 
upon the unmanured land, derived the whole of their 
nitrogen from the ground, and that nitrogenous food 
had not heen received either fi'om the air or from the 
dew ', then the profit and loss of the field in nitroge- 
nous nutriment (according to the assumptions made p. 
220, that f'o of the nitrogenous constituents in clover 
and potatoes were carried off in the form of cattle), 
may be thus represented : — 

The field at Cunnersdorf. 



1851. 

Rye corn . . . 

" straw . . . 

1852. 
Potatoes .... 

1853. 

Oat corn .... 

" straw .... 

1854. 
Clover-hay . . . 





Produced 
altogether. 


Lost by 
crop sold. 




Nitrogen. 


Nitrogen. 


lbs. 


lbs. 


lbs. 


1176 
2951 


22-4 
10-6 


22-4 


16667 


69-8 


6-9 


2019 
2563 


30-9 
6-6 


30-0 


9144 


202-1 


20-2 
79-5 



Gained by 
rain. 

Nitrogen. 



lbs. 



At the beginning of the fifth year the field was therefore richer, 
in nitrogen, by 



120 
40-5 



PKECONCEIVED NOTIONS. 
The field at Mdusegast. 



277 









Lost by crop sold. 


Gained by rain. 








Nitrogen 


Nitrogen. 


Kyc 


1851. 




lbs. 
42-7 


lbs. 


Potatoes 


1852. 




n 




Barley 


1853. 




22-2 






1854. 




12-2 

84-1 
by . . 




In 1855 the field 


was richer 


in nitrogen 


120 
35-9 



It is hardly necessary to carry tins calculation any 
further ; for all give the same result, viz. that even on 
the most unfavourable supposition, a field receives 
back, by the rain alone, actually more, certainly not 
less, nitrogenous nutriment, than it loses in the ordi- 
nary course of agriculture. 

This fact may well justify the assertion that a far- 
mer need trouble himself as little about a compensating 
supply of nitrogen, as of carbon. Both are, in fact, 
originally constituents of the air, or capable of again 
becoming air constituents, and are in the circulation of 
life inseparable from one another. 

From the presence of ammonia and nitric acid in 
rain-water we are led to infer that a source of nitrogen 
exists, which without the aid of man, supplies plants 
with this necessary nutriment. With regard to the 
other nutritive substances, such as phosphoric acid and 
potash, which of themselves are not movable, this res- 
toration from natural sources does not exist. Hence, 
we might have supposed, that when inquiry was made 
as to the causes which, in consequence of cultivation, 
diminish the productive power of land, the reason of 



278" AMMONIA AND NITRIC ACID. 

such decrease would first and chiefly have been sought 
in those nutritive substances which are of themselves 
immovable, and not in those which possess the power 
of circulation ; especially when it was ascertained that 
part at least of the latter spontaneously came back to 
the field every year. But at every stage in the dcvel- 
opement of a science, preconceived ideas will for a time 
assert their sway ; and such is the case with those no- 
tions which ascribe to nitrogen a preeminent impor- 
tance in the cultivation of land. 

In the consideration of a natural phenomenon, and 
in the investigation of its causes, we cannot tell at first 
whether it be simple or compound ; whether it be due 
to one or to several causes ; hence we are led to attrib- 
ute the results to those alone which arejirst discovered 
in operation. No long time ago, people believed that 
all the conditions of growth lay in the seed alone ^ then 
they found that water^ and next that the air, had a 
very decided influence ; bye-and-bye they ascribed to 
certain organic remains in the ground, a most impor- 
tant part in the fertility of the soil. When at length 
they discovered that, among all the substances used for 
manure, the excrements of animals and the parts and 
constituents of animals, surpassed all the rest in opera- 
tive power ; when, too, chemical analysis had shown 
that nitrogen was the chief element in these substances, 
it is not surprising that nitrogen was then esteemed the 
sole, and afterwards the principal, agent in manure. 

This process of reasoning is in accordance with na- 
ture, and cannot be found fault with. At that time, it 
was not known that the ash-constituents of plants, pot- 
ash, lime, and phosphoric acid, play as important a 
part as nitrogen in the vital processes of plants ; nay, 
not even an idea had been formed of the manner in 
which the nitrogen of nitrogenous compounds operates. 
Men simply held by the fact that horn, claws, blood, 
bones, urine, the solid excrements of animals and men, 
exerted a favourable influence ; Avhile woody sub- 
stances, sawdust and similar materials, had no effect, 
or as good as none. If in the one case the presence, of 



THE NITROGEN THEORY. 2T9 

nitrogen was the reason of activity, so in the other case 
the want of nitrogen caused the want of activity ; in 
short, by the operation of nitrogen all facts seemed to 
be harmonised and explained. 

If the nitrogenous manures depended for their ac- 
tivity upon the nitrogen which they contained, it fol- 
lowed necessarily that all of them could not possess the 
same value for the farmer, because they did not all 
contain the same amount of nitrogen ; those whicli had 
more of this substance were manifestly more valuable 
than those which had less. The amount of nitrogen 
was easily determined by chemical analysis ; hence 
arose the idea to draw up for the benefit of farmers a 
list of manures with a figure attached to each showing 
its relative value ; those which were most abundant in 
nitrogen were considered the most valuable, and stood 
highest in the list. 

In this valuation no importance was attached to the 
form which nitrogen assumed in the various manures, 
and just as little to the substances which were present 
along with the nitrogenous compound. In this list it 
was quite immaterial whether the nitrogenous combina- 
tion was in the form of gelatine, horn, or albumen ; or 
whether these substances were or Avere not accompa- 
nied by earthy or alkaline phosphates. Dried blood, 
claws, horn shavings, woollen rags, bones, rape-cake 
meal, all figured in one and the same list. 

As no definite combination was understood by the 
word ' nitrogen,' it was impossible to prove that the 
operation of nitrogenous manures bore any proportion 
to the amount of nitrogen which they contained. 

The introduction and application of Peruvian guano 
and nitrate of soda afforded the so-called nitrogen the- 
ory a foundation to rest upon ; no manure could be 
compared with guano for abundance of nitrogen, while 
it surpassed all others in tlie rapidity and strength of 
its action. The powerful effect produced by it coin- 
cided entirely with the nitrogen theory ; it correspond- 
ed with the high amount of nitrogen in the manure, 
afid chemical analysis furnished satisfactory conclusions" 



280 AMMONIA AND NITRIC ACID. 

with regard to the rapidity of its action. The fact that 
the influence of guano in increasing the crops was gen- 
erally more rapid than that of other manures contain- 
ing an equal amount of nitrogen, made it evident that 
some one of its constituents possessed a peculiar power 
which was not present in the other manures ; and this 
constituent was supposed to be more conducive than 
other nitrogenous compounds to the growth of plants. 

The discovery of this constituent presented no diffi- 
culty. Chemical analysis showed that Peruvian guano 
was very rich in salts of ammonia, and that one-half of 
its nitrogen existed in the form of ammonia. But am- 
monia was already well known as an element of nutri- 
tion for j)lants, and this afforded an easy solution of the 
rapidity which marked the operation of guano. Peru- 
vian guano accordingly contained in a concentrated 
state in the ammonia one of the most important nutri- 
tive substances for plants, and this nutriment when 
dispersed in the soil could be directly assimilated by 
their roots. 

From this time forward a distinction was drawn 
between the various kinds of nitrogenous manures, and 
' assimilable ' nitrogen was discriminated from that 
which was termed ' sparingly assimilable.' Assimila- 
ble nitrogen was understood to mean ammonia and 
nitric acid ; but the term ' hard of assimilation ' was 
applied to other nitrogenous substances, which could 
not be made effective until their nitrogen had been con- 
verted into ammonia. 

The effect of guano in raising large crops of corn 
was undeniable ; hence it was according to theory as- 
sumed as incontestable, that its operation depended 
upon the amount of nitrogen contained in it ; it was 
further considered as certain, that ammonia was the 
most effective portion of the nitrogen in guano. It fol- 
lowed, therefore, as a matter of course, that the opera- 
tion of guano could be produced by substituting a cor- 
responding quantity of salts of ammonia ; and the par- 
tisans of this theory believed that to increase corn crops 
at pleasure, nothing further was necessary than to pro- 



EXPEKIMENTS WITH SALTS OF AMMONIA. 281 

cure the requisite quantity of salts of ammonia at a 
reasonable price. Humus is the only thing wanting ; 
such was the earlier opinion. Now, it is ammonia is 
the only thing wanting. 

This conclusion was an immense step in advance as 
regards the views of the importance of nitrogen for 
plants. Instead of attaching no determinate idea to 
the word ' nitrogen,' the term had now a fixed and 
definite meaning. That which formerly was called 
nitrogen was now termed ' ammonia,' an intelligible, 
ponderable compound separable from all other sub- 
stances which are likewise constituents of nitrogenous 
manures, and capable of being used in experiments, in 
order to test the truth of the theory itself. 

If the operation of guano bore any proportion to its 
nitrogen, then a quantity of ammonia containing an 
equal amount of nitrogen must produce not only the 
same, but a much greater effect ; for one-half of the 
nitrogen in guano exists in the form which is difficult 
of assimilation, whereas the ammonia could be entirely 
assimilated. 

If in any single experiment, the guano produced a 
powerful effect, and the corresponding quantity of am- 
monia was inoperative or weaker, this experiment 
would be amply sufficient to confute the notion which 
had been attached to nitrogen. For if this notion was 
correct, the ammonia ought to operate in all cases in 
which the guano operated, and exactly in the same 
manner. The oldest experiments in this direction were 
made by Schattenmann (' Compt. rend.' t. xvii,). 

He manured ten plots of a large wheat-field with 
sal ammoniac and sulphate of ammonia ; an equally 
large plot remained unmanured. Of the manured 
plots, one received 1G2 kilogrammes (= 356 lbs. Eng.) 
per acre ; the others received the double, treble, and 
quadruple quantity of each of these salts. 

The salts of ammonia (says Schattenmann, p. 1130) 
appear to exert a remarkable influence upon wheat ; 
for, only eight days after manuring, the plant assumed 
a deep dark-green colour, the sure sign of high vegeta- 
tive power. 



282 



AMMONIA AND NITEIC ACID. 



The returns obtained by manuring with the salts of 
ammonia were the following : — 



Muriate oT Ammonia employed. 



kilo. lbs. 

(1) 1 acre . none 

(2) 1 " . 162= 356 

(3) 4 " . 324= 712 



486=1069 
Average of the four 



324= 712 
486=1069 



Sulphate of Ammonia cmplojed. 



kilo. 

(4) 1 acre . 162 

(5) 4 " .324 



486 486 

Average of the four . 



kilo. 
324 



Crop. 



kilo. cwt. 
1182=23 
1138=22 

878=17 



1174=23 
903=18 



kilo. cwt. 
2867=56 
3217=63 

3171=62 



3078=60 
3248=63 



LessCoi-n. More Straw. 



kilo. CTVt. 

44=0-8 
304=60 



8=015 
279=5-3 



kilo. cwt. 
348=6-8 

314=6-0 



211=40 

381=7-5 



It is easy to see that the expectations which had 
been founded upon the deep dark-green colour were 
not realised. The salts of ammonia were so far from 
exerting any influence in augmenting the corn-crop, 
that they diminished it in every experiment. In the 
crop of straw there was a small increase. 

In these cases the salts of ammonia had not enlarged 
the corn crop, but had produced the opposite effect 
from guano, by which corn crops are generally aug- 
mented. 

These experiments cannot, however, be regarded as 
decisive proofs against the view of the action of ammo- 
nia, because a comparative experiment with guano was 
not made at the same time and place. It is not impos- 
sible, that upon this particular field guano might have 
produced the same results. Some years later, Lawes 
and Gilbert published a series of investigations, which 
seemed to establish the operative power of ammonia, or 
rather of salts of ammonia. These investigations were 
intended to show, that the incombustible nutritive sub- 
stances of wheat were not, of themselves, sufficient to 



EXPEKIMENTS OF LAWES AJJfD GILBERT. 283 

enhance the fertility of a field, but that the crop of com 
and straw stood rather in proportion to the supply of 
ammonia. In fact, that increased crops could be ob- 
tained by salts of ammonia alone, inasmuch as nitro- 
genous manures were peculiarly adapted for the culti- 
vation of wheat. 

The experiments of Messrs. Lawcs and Gilbert are 
very far, indeed, from proving the conclusions which 
they wish to draw ; they establish rather the fact that 
tliese gentlemen have not the slightest notion of what 
IS meant by argument or proof. 

They did not attempt to discover whether salts of 
ammonia alone could produce from one portion of a 
field continuous larger crops than were yielded by an 
unmanured portion of the same field. 

Xeither did they attempt to discover what crops 
would be yielded by an equal plot of ground by ma- 
nuring with superphosjihate and potash salts during 
a series of years. But in the first year they supplied 
a plot of ground for a whole series of years with the 
constituents of corn and straw, phosphoric acid and 
silicate of potash (560 lbs. of bone-earth rendered solu- 
ble by sulphuric acid, and 220 lbs. of silicate of potash), 
and manured it, in the following years, with salts of 
ammonia only, and they would have us to believe that 
the increased crops obtained under these circumstances 
were due to the operation of salts of ammonia alone ! 

The imperfect nature of the experiments made by 
Messrs. Lawes and Gilbert will appear, perhaps, more 
striking, if the question which they pretend to solve 
is stated in another form. We will assume that the 
point to be proved was, that the high additional crops, 
yielded by a wheat field manured with guano, were 
due to the operation of the salts of ammonia in the 
guano, and that its other constituents had no share in 
the work. If the guano had been lixiviated with water, 
and two portions of a field had been manured, the one 
with guano, the other with the soluble consiltueiHs of 
an equal quantity of guano, only two cases could occur ; 
the crop of both plots would be either equal or unequal. 



284 AMMONIA AND NITEIC ACID. 

If the crops were equal, it would be manifest that the 
insoluble constituents of the guano had no effect : if the 
crop upon the plot manured M'ith guano was greater, 
it would be certain that tlie insoluble constituents 
(mineral constituents, as Messrs. Lawes and Gilbert 
would term them) had some share in prochicing the 
additional crop. The extent of this share could per- 
haps be determined, if a third plot were manured with 
the insoluble constituents, i. e. with the lixiviated resi- 
due of an equal quantity of guano. 

If an experimentalist, in carrying out his proof, in- 
stead of following this method, had, on the contrary, 
lixiviated the guano, and manured a plot of ground in 
ih^ first year with the insoluble constituents of the guano, 
and in the subsequent years, with the soluble constitu- 
ents — and if he had maintained that these soluble con- 
stituents, in other words, the salts of ammonia in the 
guano, had alone produced the high additional crops, 
and that these bore a proportion rather to the salts of 
ammonia than to the incombustible constituents in the 
guano, M'e should have good grounds for concluding 
that he had simply deceived himself ; for, in point of 
fact, the field had been manured, not with salts of am- 
monia alone, but with all the constituents of the guano. 

What has here been said in refei'ence to guano, 
which, as before mentioned, has the same effect as a 
mixture of superphosphate, potash, and salts of am- 
monia, may be literally applied to the experiments of 
Lawes and Gilbert. 

They manured their field, in the first year, with a 
quantity of soluble phosphoric acid, lime, and potash, 
which very nearly corresponds with the amount of these 
substances in 1750 lbs of guano ; and in the subsequent 
years they aj^plied salts of ammonia. The arable sur- 
face soil of the field had, by previous cultivation, been 
manifestly exhausted of nitrogenous food ; and, under 
these circumstances, the only wonder M'ould have been 
if the imtriti s^e substances which operate in guano had 
been able, without ammonia, to yield as large a crop as 
with ammonia. 



EXPEEIMENTS WITH SALTS OF AM^IO^■IA. 285 

These experiments are worth notice in the history 
of a2:ricultiire, because they show what statements could 
be laid before farmers; at a tiniowhen ignorance of first 
principles did not yet permit scientific criticism. 

With regard to the infiuence of ammonia and salts 
of ammonia there was instituted in the years 1857 and 
1858, on the part of the General Committee of the Agri- 
cultural Society of Bavaria, a series of comparative 
experiments in the district of Bogenhansen, as to the 
operation of guano, and various salts of ammonia con- 
taining an equal amount of nitrogen, the results of 
which are decisive. 

The experiments were conducted upon a field (a 
loam) which had gone through the usual rotation, and 
which, with ordinary farm-yard manure, had borne rye 
and then oats twice successively. Of eighteen plots in 
this field, each 1914 square feet in area, four were ma- 
nured with salts of ammonia, and one with guano, one 
plot remained unmanured. 

As a starting point for estimatiug the quantity of 
manure to be employed, it was assumed that 400 lbs. 
of guano per acre English ( = 493 lbs. avoir.) corre- 
spond to the full measure of farm-yard manure usually 
applied. According to this proportion, 20 lbs ( = 24f 
lbs. avoir.) of guano were reckoned for the area in 
question. 

Tlie samples of good Peruvian guano selected were 
previously analysed, and in 100 parts a quantity of 
nitrogen was found corresponding to 15*39 of ammonia. 
As a general rule, only one-half of the nitrogen in 
guano is present as ammonia ; the other half appears 
as uric acid, guanine, &c., of the oj^eration of which 
upon the growth of plants little or nothing, as we have 
before observed, is known. But it was assumed that 
the nitrogen in these other substances was just as oper- 
ative as that in the ammonia, and the quantum of the 
various salts of ammonia (which were likewise analysed 
previously to ascertain exactly 1 heir amount of ammonia) 
was reckoned in accordance with this assum])tion. Ac- 
cordingly, for the above 20 lbs. of guano, 1719 grammes 



286 AMMONIA AND NITEIC ACID. 

( = 3*75 lbs.) of ammonia were computed as the equiva- 
lent ; and each of the other four plots received exactly 
the same quantity of annnonia, in the salt of ammonia 
emjiloyed for manure. 

It is clear that if an increased crop was obtained by 
means of the guano, and if this was due to the amount 
of its nitrogen, then each of the other four plots, having 
received the same quantity of nitrogen^ must necessarily 
be affected exactly in the same manner as if they, also, 
had been manured with 20 lbs. of the same guano. The 
results were as follow : — 

Comparative experiments at Bogenhausen with guano and salts 
of a^nmonia containing equal quantities of nitrogen. 

Harvest, 1857. — Barlet. 

Grain. Straw, 

grammes, lbs. grammes. grammes. 

Manured with 5880=13 carbonate of ammonia. . 6335 16205 

" 4200= 9 nitrate " 8470 16730 

" 6720 = 141 phosphate " 7280 17920 

6720=141 sulphate " 6912 18287 

" 20 Ibs. = 24f av. guano 17200 33320 

Unmanured 6825 18375 

Although each of the four plots had received the 
same quantity of nitrogen, still their respective crops 
did not correspond ; on the whole, the crop from the 
plots manured with salts of ammonia, corn and straw 
together, was in each case very little higher than that 
of the unmanured plot ; while the plot manured with 
guano yielded, for the same quantity of nitrogen, 2^ 
times more corn, and 80 per cent, more straw, than the 
average crop of the plots manm'cd with salts of am- 
monia. 

In the subsequent year, this experiment was re- 
peated in a similar manner in the same district with 
winter wheat. The field chosen, and to which six 
years previously farm-yard manure had been applied, 
had borne winter rye, then clover, and then oats, for 
three years. The oat stubble was broken up and then 
twice ploughed : on the 12th September, 1857, the seed 



BOGENHAUSEN EXPERIMENTS. 287 

was sown and harrowed in, on one day : immediately 
after the sowing there was a moderate thunder shower. 
The field was divided into seventeen lots, each of 
1900 square feet, which were separated from each other 
by furrows ; each was separately sown and harrowed. 
The quantity of guano used was 18'8 lbs. ( = 23"3 lbs. 
avoir.), and the weight of the salts of ammonia employed 
was calculated from the amount of nitrogen in the guano, 
so that, as in the previous experiment, each plot received 
an exactly equal amount of lutrogen. The results were 
the following : — 

Experiment in Bogenhausen. 

Result of Harvest, 1858. — Wixter-wheat. 

Corn. Straw, 

grammes. grammes. 

Manured with guano, yielded 32986 79160 

" sulphateof ammonia (11 -S lbs. Bav.).. 19600 41440 

" phosphate " (11-9 " " ).. 21520 38940 

" carbonate " (10-6 " " ).. 25040 57S60 

" nitrate " ( 7-1 " " ). . 27090 65100 

Umnanured 18100 32986 

These experiments show in the clearest manner that 
it is an error to refer the effect of a powerful nitroge- 
nous manure chiefly to the nitrpgen which it contains. 
Ko doubt it has a share in the operation of these ma- 
nures, but their energy is not in proportion to the 
amount of nitrogen in them. 

If ammonia or salts of ammonia increase the prod- 
uce of a field, their effect depends upon the nature of 
the soil. What we mean here by the nature of the soil 
is understood by every one ; the ammonia can engender 
in the soil no potash, no phosphoric acid, no silicic acid, 
no lime ; and if these substances, which are indispensa- 
ble for the developement of the wheat plant, are not 
found in the soil, the ammonia cannot produce any 
effect whatever. If, then, in Schattenmann's experi- 
ments, and those at Bogenhausen, there were no results 
from the salts of ammonia, this did not arise from the 
fact of these salts being in themselves ineffective ; but 
they were inactive, because the conditions of tlieir ae- 



288 AMMONIA AND NTTEIC ACID. 

tivity we^-e wanting. Lawes and Gilbert supplied these 
conditions to their field, and hence ensured activity to 
the ammoniacal salts they used. 

The results obtained by Kuhlmann respecting the 
effect of salts of ammonia upon meadows are precisely 
similar. He manured a piece of meadow land with 
sulphate of ammonia, and obtained a crop of hay larger 
than tlie yield of the unmanured plot, because a certain 
quantity of phosphoric acid, potash, &c. was rendered 
active, which without the cooperation of salts of am- 
monia, would not have been the case. On adding 
phosphate of lime to the salts of ammonia, the activity 
of the latter was enhanced in an extraordinary degree ; 
he obtained, — 

Return of harj, per hectare, 1844, 

Excess above the 
unmanured plot, 
kilo. kilo. kilo. 

(1) By manuriug with 250 sulphate of ammonia . . 5564 1744 

(2) " " 333 sal ammoniac, with phos- 

phate of lime 9906 6086 

(3) Unmanured plot 3820 — 

Thus, by sulphate of ammonia alone, Kuhlmann ob- 
tained rather more than half as much hay again as the 
yield of the unmanured plot ; and by adding phosphate 
of lime he gained almost three times as much. 

Those who maintained the theory of the special im- 
portance to agriculture of nitrogen in manure, formed 
a similar notion about the cause of fertility in land. 

If, in fact, the efficacy of any manure depended on 
the enrichment of the soil with nitrogen, exhaustion 
could be explained only by the diminution of the store 
of nitrogen ; and the manure would restore fertility 
when the nitroien which had been removed in the har- 
vest was again supplied by it to the field. Accordingly, 
the unequal fertility of land must be due to the unequal 
amounts of nitrogen contained in it ; and it would fol- 
low that the soil richer in nitrogen must be more fruit- 
ful than one which contained less of this element. 

This theory, too, came to a pitiful end ; since that 



FERTILITY OF LAND NOT DUE TO ITS NITROGEN. 289 

which was not true for manures could not possibly hold 
good for land. 

Every one who is acquainted with chemical analysis 
knows that among the constituents of the soil none can 
be approximately determined with greater accuracy than 
nitrogen. In an exhausted soil at Weihenstephan and 
Bogcnhausen, nitrogen Avas determined by the usual 
method, and calculated to a depth of 10 inches. 

The field contained, per hectare, 

Bogcnhausen. Weihenstephan. 
kilogr. kilogr. 

Nitrogen 5145 5801 

On both fields summer barley was cultivated in 
1857, and the following returns were obtained, per hec- 
tare : — 

Bogenhausen. Weihenstephan. 
kilogr. kilogr. 

Corn 413 1604 

Straw 1115 2580 

1528 4184 

Thus, the field at "Weihenstephan, containing about 
the same amount of nitrogen, yielded almost four times 
as much corn, and more than twice as much straw, as 
the field at Bogenhausen. 

In 1858, these experiments were repeated at Weihen- 
stephan with M'inter wheat, and at Schleissheim with 
winter rye ; the result was : — 

Nitrogen contained to the depth of 10 inches, per hectare, 

Schleissheim. Weihenstephan. 

kilogr. kilogr. 

2787 5801 

Crop. 

Com 115 1699 

Straw 282-6 3030 

397-6 4729 

The amount of nitrogen in the field at Schleissheim, 
as compared with that at Weihenstephan, bears the 

13 



290 AMMONIA AND NITEIC ACID. 

proportion of 1 : 2 ; whereas tlie crops are in the pro- 
portion of 1 : 14. These facts are fatal to the opinion 
that there exists any connection between the amount 
of nitrogen in a soil, and its powers of production ; and 
in truth no one now entertains this belief. For since 
Kroker in 1846 determined the nitrogen in 22 kinds of 
soil from various districts, and discovered that even an 
unfruitful sand contained more than a hundred times, 
while in arable soils to a depth of 10 inches there were 
present from 500 to 1000 times, more nitrogen than is 
necessary for a good crop, similar investigations have 
been made in all countries, and Kroker's results have 
been confirmed. 

Since that period the fact has been generally ad- 
mitted, that the great majority of cultivated soils are 
far richer in nitrogen than in phosphoric acid ; and 
that the relative proportion of nitrogen present, which 
had been adopted as the standard for calculating the 
value of manure, was quite inapplicable for estimating 
the productive power of land. 

Hence, between the chemical analysis of manures, 
and that of the soil, there arose an irreconcilable con- 
tradiction. In the chemical laboratory the efiective 
Value of a manure could be accurately determined ac- 
cording to the per centage of its nitrogen ; but w^hen 
the farmer had incorporated his manure with the soil, 
the determination of the per centage of nitrogen in the 
ground was no longer of any use in estimating its pro- 
ductive power. 

This strange circumstance might well have excited 
suspicion against the theory of the preponderating in- 
fluence of nitrogen, for which, as already observed, there 
is not the slightest evidence in point of fact. But in- 
stead of this, the advocates of the theory maintained it 
steadfastly, and endeavoured to explain the behaviour 
of the soil upon new and still more extraordinary 
grounds. It had been observed that a very small frac- 
tion of the quantity of nitrogen present in the soil, in 
the form of guano, farm-yard manure, or nitrate of soda, 
materially increased the crops ; whereas, the effect of 



DIFFERENT FORMS OF NITROGEN IN TUE SOU.. 201 

other manures, which contained nitrogen not in the 
form of ammonia or nitric acid, was very unc(|iud in 
respect of time, and, in the ease of horn shavings or 
M'ooilen ra<'S, "vvas extremely slow. This led to the 
assumption that the nature of nitrogen was as variable 
in the arable soil as in manures ; one portion was sup- 
posed to be in the form of ammonia or nitric acid, and 
this was, properly speaking, the effective part ; another 
portion, on the contrary, existed in some peculiar turni 
which could not exactly be defined, and was quite in- 
effective. 

Hence the productive power of a soil was, according 
to this view, not in proportion to the entire quantity 
of nitrogen in it, but could only be measured by the 
nitric acid and ammonia which it contained. As the 
advocates of the theory about the effective operation 
of nitrogen had been accustomed to shirk proving the 
truth of their doctrine, as a matter of course they did 
not trouble themselves about adducing any positive 
facts in support of this extension of it. They believed 
that they could establish their point in the following 
way. 

When a crop contained in corn and straw as much 
nitrogen as was equivalent to six, four, three, or two 
per cent, of the whole quantity of nitrogen in the soil, 
the reason was that there were present in the field six, 
four, three, or two ])er cent, of active nitrogen, while 
the remaining 94, 90, 97, or 98 per cent, were inoper- 
ative nitrogen. 

Tlie cause of the effect (the amount of active nitro- 
gen in the soil) was consequently interred from the 
effect (the amount of nitrogen in the crops). If more 
of the whole quantity of nitrogen was in an active form, 
then higher crops would follow ; if the crops were lower, 
the reason was that there was a deficiency of active 
nitrogen. If in guano or farm-yard manure additional 
active nitrogen was supplied, the crops would be in- 
creased. 

By taking a new standard for estimating tlie ])ro- 
ductive power of the soil, the former one for the valu- 



292 AMMONIA AND NITRIC ACID. 

ation of manure was virtuallj abandoned. For when 
efficiency was allowed only to nitric acid and ammonia 
in the soil, and denied to all other nitrogenous combi- 
nations, it was evidently unwarrantable to place those 
nitrogenous compounds in manures, which were neither 
ammonia nor nitric acid, in the same class with these 
two elements of Ibod. 

But in the classified estimate of manures, a high 
place was given to dried blood, horn shavings, gelatine, 
and the nitrogenous constituents of rape-cake, all sub- 
stances which contain neither nitric acid nor ammonia. 
The favourable effect of these manures was, in the ma- 
jority of cases, undoubted, but still not determinable 
by analysis. Of two fields, the one manured with rape- 
cake, the other not, the former yields a larger corn or 
turnip crop than the latter, but it is not possible to 
show that there was more ammonia in the one case 
than in the other. True, it was assumed that the nitro- 
genous compounds of these manures, the albumen of 
the blood, the rape-cake, or the gelatine, was gradually 
converted into ammonia, and so became operative ; but 
it was taken for granted as a matter of course, that the 
so-called inoperative nitrogenous compounds present in 
the soil do not possess the power of yielding ammonia, 
or of being oxydised into nitric acid. 

It was well known, indeed, that if one of two fields 
contained more lime than the other, the one richer in 
lime, often did not on that account produce more clover. 
Yet no one thought of assuming that the lime in the 
richer field existed in a two-fold condition, operative 
and inoperative, or that the active portion of the lime 
had caused the difiference in the clover crops. 

It was also well known that if two fields be manured 
with the same bone-earth, the one often gave a higher 
crop than the other, and yet no one thought of assum- 
ing that in the second field the inefficiency of the bone- 
earth was due to the fact that it had passed into a state 
of inactivity. 

It was further known, that the excess of no individ- 
ual nutritive substance exercised any influence upon 



NITKOGEN IS NOT UNDER TWO FORMS IN SOILS. 293 

the produce of a field ; but it was assumed that the 
case must be different with nitrogen. A surphis of that 
element, it wiis surmised, must act, and if it did not, 
the cause was not ascribed to the field, but to the na- 
ture and condition of the nitrogenous compounds. 

From this we see that the notion of nitrogen exert- 
ing the princi]3al influence in agriculture led to unex- 
ampled confusion of thought and to the most baseless 
and absurd suppositions. JS'one of the advocates of this 
theory gave themselves the slightest trouble to extract 
from the ground one of the nitrogenous compounds, 
which were deemed inoperative, so as to study its na- 
ture j but properties were ascribed to them, of which 
nothing could be known, because the things themselves 
were not known. 

As the advocates of this theory can say nothing 
about the nature of the nitrogenous compounds present 
in the ground, they w^ant to make us believe that noth- 
ing at all is known about them. But no one, who has 
an acquaintance with chemistry, has the smallest donbt 
or uncertainty respecting the origin of nitrogen in the 
arable soil, it is derived either from the air, whence 
it is conveyed to the earth in rain or dew ; or from or- 
ganic substances accuumulated from a series of gener- 
ations of dead and decayed plants, or else from animal 
remains contained in the earth, or incorporated with it 
by man in the form of excrements. Animal and human 
excrements, bodies of animals in the earth, corpses in 
their cofiins, all vanish, with the exception of their in- 
combustible matters, after a series of years ; the nitro- 
gen of their constituents is converted into gaseous am- 
monia, and is distributed in the surrounding soil. Tlie 
remains of extinct animal life which are embedded, to 
an enormous extent, in sedimentary strata, or which 
of themselves constitute whole masses of rock, attest 
the extraordinary distribution of organic life in the 
former ages of the earth ; and it is the nitrogenous con- 
stituents of these animal bodies, passing over into am 
monia and nitric acid, which still play an important 
part in the economy of the vegetable and animal world. 



294 AMMONIA AND NITRIC ACID. 

If the smallest doubt could exist on this question, 
it is completely removed by the investigations of Sclimid 
and Pierre (' Compt. rend.' t. xlix. pp. 711-715). 

Schmid examined (see Peters. ' Acad. Bull.' viii. 
161) several specimens of Russian black-earth (tscherno- 
sem) from the Government of Orel, and among them 
three from the same field, marked by him as ' virgin 
soil,' of which we may assume that it had never been 
subject to agricultural operations ; the amount of nitro- 
gen in tliis soil amounted to — 

Amount of nitrogen in the tschei'n-o-sem. 

Under the turf 0'99 per cent, nitrogen 

4 werschoks (= V inches) deeper. . 0-45 " " 

Above the subsoil 0-33 " " 

If we assume a cubic decimetre ( = 61 cubic in.) of 
this earth to weigh 1100 grammes ( = 2*4 lbs.), then, 
calculating for the area of a hectare ( = 2^ acres), the 
ground would contain — 

kilo. cwt. 
1 decimetre (= 4 inches) deep .... 10890 = 213 nitrogen 

1 " " deeper 4950 = 97 " 

1 " " " 3630 = 71 " 



30 centimetres (= ll-'Z inches) deep. . 19470 = 381 " 

In examining a soil in the neighbourhood of Caen, 
Pierre found in it 19620 kilogrammes ( = 385 cwt.) of 
nitrogen distributed, in the following manner, through 
a hectare to the depth of one inetre ( = 3*3 feet.) 

centimotres. inches. kilogr. cwt. 

In the first layer of 25 =10 deep, the soil contained 8360 = 164 

" second " 25—50 = 10—20 " " 4959 = 97 

" third " 50—75 = 20—30 " " 3479= 68 

" fourth " 75—100 = 30—40 " " 2816= 65 



19614=384 



Thus, according to both investigations, the uppermost 
layers, or the proper arable soil (about 10 inches deep), 
were the richest in nitrogen, while in the lower layers 
the amount decreased. 



NITKOGEN IN TUE DIFFERENT LAYERS OF SOILS. 295 

Such a condition undeniably proves the origin of 
nitrogen in the arable soil. 

If the upper layers which are constantly deprived 
of nitrogen by cultivation, contain more of this element 
than the lower, it necessarily follows that the nitrogen 
must have come from without. The analysis of the 
most various kinds of soil in many different lands and 
districts shows that there is scarcely a single fruitful 
wheat soil which docs not contain at least 5000 to 6000 
kilogrammes ( = 98 to 118 cwt.) of nitrogen per hec- 
tare ( = 2^ acres) to the depth of 25 centimetres (= 10 
inches) ; and the simplest comparison of the quantity 
of nitrogen in the soil, with that which is removed in 
the crops, proves that the latter amounts to a very small 
fraction, and that the land is exhausted of all other 
nutritive substances sooner than of nitrogen. 

The experiments of Mayer (' Ergeb. landw. u. agric. 
Ycrsuche.' Miinchen. Iter Heft, s. 129) show that the 
beiiaviour of arable soil with respect to alkalies in 
watery solution affords no conclusion as to the nature 
of the nitrogenous compounds therein contained. It 
had been assumed, that all nitrogen in the earth in the 
form of ammonia could be separated by distillation 
with caustic alkalies, and that the portion that was not 
thus separated did not exist as such. Mayer proved 
the incorrectness of this assumption ; he first discovered, 
that many earths rich in humous constituents when 
boiled for four hours (which may be considered equiva- 
lent to lixiWation for four hours wath boiling water) 
still retained a very considerable quantity of ammonia. 
The earths employed in these experiments were (1) earth 
from the hollow trunk of a tree, (2) garden soil rich in 
organic matters, from the Botanic Garden, (3) strong 
clay soil from Bogenhausen. 

A^nmonia. 

One million milligrammes ( = 2-2 lbs.) retained at the temperature of 

boiling water: 

milligr. grs. milligr. pn: milligr. gre. 

(1) Tree soil, 7308 = 112 (2) Garden soil, 4538 = 70 (3) Clay, 1570 = 2-t 

If an arable soil after saturation with ammonia, by 



296 AMMONIA AND NITEIC ACID. 

being placed either in a weak solution of pure ammonia, 
or in a confined space with ammoniacal gas, or over 
carbonate of ammonia, is then dried and exposed in 
thin layers in this dry state to the air for fonrteen days, 
all the ammonia not intimately combined in the soil is 
evolved, and the same result may be i3rodnced by con- 
stant washing with cold water. Now if soils thus satu- 
rated, the ammonia of which has been accurately ascer- 
tained, are exposed to distillation with soda lye, it is 
found that a considerable portion of the absorbed am- 
monia is not separable in this way. In the following 
table, A expresses the quantity of ammonia respectively 
absorbed by various soils at the ordinary temperature 
of the air ; B, the quantity of ammonia retained by the 
same soils after twelve to fifteen hours' action of soda 
lye in a water bath. 

One million milligrammes ( = 2"2 lbs.) of soil from 

Havannah. Schleissheim. Bogenhausen. Clay soil. 

milligr grs. milligr. gra. miliigr. grs milligr. grs. 

A Ammonia... .5520^85 3900=60 3240 = 50 2600 = 40 

B " ... 920 = 14 970=15 990=15 470= 7 

Under these circumstances, it appears that the 
power of retaining a certain portion of the absorbed 
ammonia is very unequal ; tlui Havannah earth (a poor 
lime soil) retains a sixth of the absorbed ammonia, the 
soil at Schleissheim the fourth, that at Bogenhausen 
almost a third.* 

* We need not be surprised at this peculiar comportment, for it merely 
proves that part of the ammonia in the earth is contained in an entirely 
diiferent form from that of a salt. The salts of ammonia are combinations 
of ammonium, which can be easily decomposed by alkalies, alkaline earths, 
and metallic oxides, the alkali taking the place of oxide of ammonium, or 
the ammonium being displaced by some other metal. But we have no 
reason to believe, that the ammonia, which by physical attraction is fixed 
in the porous arable soil, yields its place to another body, and is separable 
by it, if the latter has not a stronger attraction for the soil. 

Carbonate of lime, in the cold, produces scarcely any effect upon sul- 
phate of ammonia ; but in an arable soil, which contains carbonate of lime, 
the salt of ammonia is completely decomposed : lime takes the place of the 
ammonia, the latter however does not become free, but enters into some 
other combination, upon which lime has no effect. 



AMMONIA RETAINED FIRMLY BY SOILS. 297 

Tliis explains the reason why an arable soil saturated 
with ammonia gives back only a portion after being 
heated with soda lye for several hours ; and it is rather, 
perhaps, the lengthened operation of water at a high 
temperature, than the chemical attraction of the soda, 
that gradually separates, in the form of gas, the am- 
monia fixed by the soil. In this operation there is no 
perceptible limit, where the evolution of ammonia 
ceases ; for even after twenty -five hours of continuous 
heating in a water-bath, the fluid which passes ofi" has 
still an alkaline reaction. 

The above arable soils in their natural condition 
comport themselves with a boiling solution of soda 
precisely as if they were partially saturated with am- 
monia. " In the following table, A expresses the total 
quantity of nitrogen in the form of ammonia, which is 
obtained from various soils at a red heat with soda 
lime ; B, the cpiantity of ammonia which is separable 
from them after twelve to twenty-five hours' heating 
with a solution of soda. 

One million milligrammes of earth = ( 1 kilo. = 2-2 lbs.) from 





Havannah. 


Schleisshcim, 


Bogenhausen. 


Clay soil. 




milligr. grs. 


milligr. grs. 


milligr. grs. 


milligr. grs: 


A 


2640 = 40-6 


4880 = 75.0 


4060 = 62-5 


2850 = 44-0 


B 


.... 510= 7-8 


1270 = 19-5 


850 = 12 


830=12-7 



These numbers lead to some interesting consider- 
ations ; they show, among other things, that the third, 
fourth, or fifth part of all the nitrogen contained in the 
soil is separable in the form of ammonia ; and that after 
twenty-five hours' distillation with a solution of soda, 
the fluid which passes off has still an alkaline reaction. 

As a soil saturated with ammo7iia retains, after five 
or six hours' heating with a solution of soda, a third, 
a fourth, or a sixth of the ammonia absorbed by it, and 
we cannot assert that the retained portion has changed 
its nature, and is no longer ammonia ; so from the com- 
portment of the earth in its natural condition, and under 
the same circumstances, we cannot conclude that the 
nitrogen which by distillation cannot be obtained in 

13* 



298 ' AMMONIA AND NITRIC ACID. 

the form of ammonia, does not, therefore, exist as such 
in the earth. 

Even if the experiments above described do not 
afford any proof tliat all the nitrogen in the ground is 
in tlie form of ammonia (a portion, besides, is in most 
cases present as nitric acid), there is, on the other hand, 
no proof fnrnished to the contrary. 

Strictly speaking, the discussion of the point in 
question does not depend on this proof ; for it is suffi- 
cient to show here, that the comportment of the soil 
; with respect to the amount of nitrogen in it is exactly 
the same 'as that of farm-yard manure. Only a small 
portion of the nitrogen in farm-yard manure, is sepa- 
rable by distillation with alkalies ; the much larger por- 
tion being obtained only by complete decomposition of 
the substances. 

According to Yoelker's analysis, 800 cwt. of fresh 
farm-yard manure contained — 

1854, November. 1855, April, 
lbs. lbs. 

Nitrogen 514 712 

Ammonia ]|^^^^^,^j;2J:2 I gve V4-4 

If we compare with this the amount of separable 
ammonia and the total nitrogen in the soil at Schleiss- 
heim and Bogenhausen, we have — 

Sohleissheim. Bogenhausen. 
lbs. lbs. 

800 cwt. of arable soil contain nitrogen 32r6 267-2 

Present as separable ammonia 101'6 68"0 

It is manifest, that when two soils, not particularly 
rich in nitrogen, contain just as much ammonia as an 
equal weight of farm-yard manure, if we ascribe the 
effect of the latter merely to the amount of ammonia 
which it contains, then the unfruitfulness of the field 
at Schleissheim is entirely inexplicable. 

We assume that the entire quantity of nitrogen in 
farm-yard manure has a definite share in its operation ; 
and as the nitrogenous matters in the arable soil are 
originally identical with the substances which form the 



CROPS NOT IN PKOPOKTION TO NITROGEN IN SOIL. 299 

const itucuts of manures, it is impossible to ascribe to 
the one an effect which does not equally apply to the 
other. 

There can be no doubt that the nitrogenous com- 
pounds in the ground often exert no influence in increas- 
ing the cro])s, Avhile those in the manures luidoubtedly 
produce a favourable effect. Hence the operation of 
the nitrogenous compounds in the manure must liave 
depended upon causes which the ground did not sup- 
ply ; and it is clear that the same efficacy can be given 
to the nitrogenous compounds in the soil, if the farmer 
will take care to bring into play the causes which pro- 
duced the favourable operation in the manures. 

If we consider, for example, the crops yielded (see 
pp. 148 and 151) by the two fields at Schleissheim in 
an uumanured condition, and compare them with the 
quantity of nitrogen in the soil, the result is — 

Nitrogen, per hectare (= 2|^ acres). 
To the depth of 10 inches. Produce. 







Corn. 


Straw. 


In Field 1 (p. 151), 1858 . 


.. 21S1 kilo. 


115 kilo. 


282 kilo. 


In Field 2 (p. 148), 1857 . 


.. 4*752 " 


044 " 


1656 " 



Those who maintain that the crops depend upon 
the nitrogen in the soil, would judge the results of these 
two experiments somewhat in the IbUowing way : — 

The amount of nitrogen in both fields is as 100: 160 

The corn crops as 100 : 560 

If the crops are in proportion to the quantity of 
effective nitrogen in the soil, it follows that the soil of 
Field 2 contained, not only altogether, but even propor- 
tionately, more than Field 1. If the corn crop in Field 
1 = 115 kilogrammes corres])onded to the fraction of 
effective nitrogen in the whole amount of nitrogen = 
2787 kilogrammes, then Field 2 ought to have yielded 
257 kilogrammes of corn, supposing that the relative 
proportion of active and inactive nitrogen were the 
same as in Field 1 (for 2787 kilogrammes, nitrogen : 
115 kilogrammes, com = 4752 kilogrammes, nitrogen: 



300 ASIMONIA AND NITRIC ACID. 

257 kilogrammes, corn). But, in fact, Field 2 yielded 
two and a half times as much corn ; and therefore the 
amount of active nitrogen in Field 2 was just in the 
same proportion greater. 

This explanation, very simple in itself, is, however, 
opposed by the fact that both these fields manm-ed in 
the same year with superphosphate of lime (prepared 
from phosphorite) (see pp. 148 and 151), gave the fol- 
lowing returns : — 

Crop, per hectare. 

Corn. Straw, 

kilo. cwt kilo, cwt 

1858. Field 1 manured with superphosphate of lime 054 = 12-8 1341 = 26*5 

1857. " 2 " " 1301 = 25-5 3813 = 75-0 

Hence, by the application of three nutritive sub- 
stances, sulphuric acid, phosphoric acid, and lime, with- 
out any increase of the quantity of nitrogen in the soil, 
as much corn was obtained from Field 1, containing 
27S7 kilogrammes, nitrogen, as from Field 2, containing 
4752 kilogrammes. There was then in the former as 
much eifective nitrogen as in the latter, but it was 
deficient in certain other substances indispensably 
necessary to produce an action. Its power to become 
active was first exliibited when these substances were 
added to the field. In like manner, the favourable in- 
fluence of superphosphate upon Field 2 was exhibited ; 
for the crop of this plot, when unmanured, did not cor- 
respond to the amount of active nitrogen which it con- 
tained; but by the addition of superphosphate the crop 
rose to more than double. And when to the super- 
phosphate upon Field 1, 137 kilogrammes of common 
salt, and 755 kilogrammes sulphate of soda were added, 
there was a still greater increase, i. e. there were now 
700 kilogrammes of corn, and 1550 kilogrammes of 
straw, a still greater quantity of apparently inactive 
nitrogen having been rendered eff'ecitive. 

The intelligent farmer who reflects upon questions 
of this kind, will be led to the conclusion, that an essen- 
tial difference may exist between his own practical 
ex[)erience and the theories of the school which seeks to 



CAUSE OF INACTIVITY OF NITROGEN IN SOILS. 301 

explain them. "Wlien jiractice tells lis that fann-jard 
manure, gniano, and bone earth have restored or in- 
creased the crops in certain cases, no one can maintain 
that these are not real facts, or are not trustworthy. 
But the observations of the practical man extend no 
further than these facts ; he has not actually remarked 
that the increased crops were produced by the annnonia 
in the farm-yard manure, or by that in the guano, or by 
the nitrogen in the nitrate of soda ; all this he is led to 
believe by persons who themselves know nothing about 
the matter. 

It is certainly a most remarkable circumstance, oc- 
curring in no other trade or industry, that in most cases 
the farmer cherishes representations or theories, for the 
truth of which he has no evidence ; nay, he seems even 
to give up completely the very idea of inquiring into 
their correctness. It is quite incomprehensible that he 
should allow himself to be guided and convinced by 
facts which have not been remarked by himself upon 
his own ground, but have been observed in altogether 
different districts, and which must at least remain 
doubtful as far as their application to his own land is 
concerned. 

If, during the last ten years, only one farmer in a 
thousand had resolved to institute experiments upon his 
own land w^ith ammonia or salts of ammonia to test the 
theory, whether in fact this manure is useful beyond all 
others in increasing the corn crops, how soon and how 
easily would an accurate estimate have been formed of 
its true value by other farmers ! 

The simple reflection that not one of the substances 
nutritive to plants does of itself exert any influence 
upon their growth, and that several other substances 
must be present, if the first is to prove useful, should 
have brought him to the conclusion that the case cannot 
be otherwise with nitrogen ; and that the value of a 
manure cannot be measured by the amount of nitrogen 
wdiicli it contains ; for this presupposes that the nitro- 
gen possesses an operative power, which must manifest 
Itself under all circumstances, and that the money 



302 AMMONIA AND NITKIC ACID. 

which the farmer lays ont in its purchase "will always 
ensure an adequate return. 

Now, when his common sense tells him that such a 
supposition is impossible, and that he has only to open 
his eyes to observe by innumerable facts that ammonia 
is no exception to other nutritive substances, he will of 
himself come to the conclusion that the inactivity of 
the great mass of nitrogen in his field is not due to any 
condition peculiar to itself, which science can ncitlier 
investigate nor explain, but that it is inactive, just as 
phosphoric acid, potash, lime, magnesia, silicic acid, and 
iron, are inactive, when there is wanting in the ground 
one of the conditions necessary to make them available. 

The tlieory that by far the greater portion of the 
nitrogen in the ground is incapable of serving for the 
nutrition of plants, cannot be proved by the fact that 
the crops do not bear any proportion to the amount of 
nitrogen in the soil ; for were this the case, then all 
soils must be equally abundant in all other conditions 
for the growth of plants, and everywhere possess the 
same geological and mechanical condition. But this 
assumption is impossible, for on the whole surface of 
the globe there are not two districts in which the soils 
are identical in these respects. 

This tlieory must be strenuously opposed, not only 
because it is false generally, and that it has never yet 
been proved to be true even in a single case, but still 
more on account of the pernicious influence which it 
exercises upon the practice of the farmer. For since it 
induces him to suppose that it is impossible to give the 
necessary efficacy to the store of nitrogen in his land, 
he will never think even of attempting to do so. Being 
convinced beforehand that he need not try to raise the 
treasure buried in his field, he never even makes the 
attempt. 

Since the exact observation made in the cultivation 
of entire countries and divisions of the globe for centu- 
ries past, and also well-established facts, make it prob- 
able that a source of nitrogenous food exists, which en- 
sures annually to a cultivated field without the husband- 



SUPPLY OF AMMONIA FKOM THE AIR, 303 

man's aid the return of a portion of the nitrogen, and in 
a rotation the whole amount of that substance which 
has been taken away in the crops ; and further, that 
the liekl may bo exhausted of every other nutritive sub- 
stance, however great its store in the ground may be, 
because tliey are never spontaneously restored to the 
soil by nature — whereas this can never happen to nitro- 
gen ; then it is contrary to all the rules of logic in any 
given case, to ascribe without closer examination the 
exhaustion of a soil above all other things to a loss of 
nitrogen. 

We might suppose that, apart from the suggestions 
of common sense, the palpable advantage which would 
accrue to the farmer imperatively demands that he 
shoukl take all possible pains to verify the correctness 
of this fact, and to discover how much nitrogenous 
food is annually restored to him by the atmosphere. 
For when he knows how far upon the whole he may 
calculate upon this source, he can easily arrange his 
system of cultivation to make it most profitable to him. 
If the atmosphere supplies him with the whole amount 
of nitrogen which he removes from his field by a rota- 
tion, then he can direct his thoughts to the means of 
keeping his whole farming operations going in the most 
effectual manner with the store which he annually col- 
lects in his manure heap, without s})ending any money 
upon nitrogenous food for his plants. If he finds that 
the atmosphere restoi-es only a portion of that which 
has been taken away, and he accurately knows what 
this portion amounts to, then as circumstances require, 
he can, with judicious economy, supply from other 
sources what is lacking ; or he may so arrange his sys- 
tem of cultivation as to make the supply of nitrogen 
from natural sources cover what is removed in the 
crops. 

Every advance in an industrial pursuit has a definite 
standard of value in the price of the products ; and no 
sensible man would call an alteration in the nu)de of 
conducting a business by the name of improvement, 
unless the price of the products covered the cost of pro- 



304 AMMONIA AND NITRIC ACID. 

duction. "When the price of g-nano exceeds a certain 
limit, so that the crop realised does not bear a proper 
proportion to the ontlay of capital and labour, this very 
circumstance prevents its application. 

From this point of view farmers might long ago 
have perceived that the question about the necessity of 
supplying ammonia to increase the crops of corn, in- 
cludes another question, whether, on the whole, prog- 
ress in this respect is, or is not, possible in agricultural 
practice. 

A few considerations only are necessary to bring 
the farmer to the conviction, which I myself entertain, 
that if increased production depends upon an augmen- 
tation of nitrogenous food in the soil, we must at once 
renounce all idea of improvement. For my own part, 
I am much more inclined to believe, that progress is 
only possible and attainable if the farmer restricts him- 
self to that store of nitrogen which he can collect upon 
his own ground, avoiding as much as possible all pur- 
chase of nitrogenous food from other quarters. 

On the average, all the experiments of Lawes in 
England have shown, tha,tfor one jpoxind of salts of am- 
monia in m^anures, tivo pounds of ivheat may he reaped. 

Tliese results, we must remember, were obtained 
from a field in which one acre without manure of any 
kind was able to yield, for seven years consecutively, 
1125 lbs. of corn and 1756 lbs. of straw ; and that all 
the plots manured with salts of ammonia also received 
phosphate and silicate of potash.* 

On an average, Lawes manured his fields with 3 
ewt. of salts of ammonia, and thereby he obtained half 
as much corn again as the unmanured plot yielded. 

We will now assume that the extra crop obtained 
was exclusively due to the salts of ammonia ; we will 

* On this point Lawes says (' Journal of the Royal Agr. Soc. of Eng.,' 
V. xiv. p. 282), that for the production of one bushel of wheat (=64 to 65 
pounds, containing 1 pound of nitrogen) which the soil was made to yield 
above its natural power, 5 pounds of ammonia were requisite ( = 16 pounds 
of sal ammoniac, or 20 pounds of sulphate of amruonia). He adds, how- 
ever, that in no single experiment did the extra crop obtained correspond 
to this estimate. 



CALCULATION OF AMMONIA KEQUIKED FOK SAXONY. 305 

further suppose that all soils are inexhaustible in plios- 
plioric acid, potash, lime, tfcc. ; and consequently, tliat 
tlie continuous application of salts of ammonia ^\•ould 
involve no exhaustion of the soil. If we now reckon 
liow much salts of ammonia, by "weight, would be 
necessary for the kingdom of Saxony, in order to obtain 
half as much corn again as the unmanured land j)ro- 
duccs, the result is the following : — The kingdom of 
Saxony comprised, in the year 1843, 1,344,474 acres 
(1 acre = 1"368 Eng. acre) of arable land, exclusive of 
vineyards, gardens, and meadows. If we suppose that 
each acre yields one corn-crop in two years, and that 4 
cwt. salts of ammonia had to be applied in the way of 
manure, the kingdom of Saxony would require annually 
2,688,958 cwt. = 134,447 tons of salts cf ammonia. 

Those who possess even a slender acquaintance with 
chemical manufacture, and know from what raw ma- 
terials (animal refuse and gas water) salts of ammonia 
are procured, must easily see that all the manufactories 
in England, France, and Germany put together, could 
not produce so muc;h as the fourth part of the salts of 
ammonia required by comparatively a very small coun- 
try, in order to increase its products in the manner pro- 
posed. 

With a similar distribution we can easily calculate 
how much salts of ammonia would be required for the 
German provinces of Austria with 11 million jochen 
(1 joch = 1'422 Eng. acre) of arable land ; for Prussia, 
with 33 million morgen (1 morgen = 0-631 Eng. acre) ; 
for Bavaria, with 9 million tagwerk (1 tagwerk = 0*842 
Eng. acre) ; and even if it were possible" to quadruple 
the manufacture of salts of ammonia, this would have 
no material influence upon the crops. 

The cheapest ammonia is conveyed to Europe in 
Peruvian guano, which, taking a high average, contains 
16 per cent. 

Peruvian guano is principally used in the cultivated 
lands of Europe, as in England, France, the Scandina- 
vian countries, Belgium, the Netherlands, Prussia, and 
the German States, comprising, exclusive of Austria, 



306 AMMONIA AND NITRIC ACID. 

120 millions of inliabitants. ISTow if we suppose that 
upon these lands for centuries to come 6 million cwt. 
( = 300,000 tons) of Peruvian guano, containing 360,- 
000 cwt. of ammonia, were annually applied, and that 
it was possible, with the means at present at our dis- 
posal, by 5 lbs. of ammonia to raise 65 lbs. additional of 
wheat, or its equivalent value, then the increased crop 
of corn would just reach so far as to give each individ- 
ual in the community 2 lbs. of corn a day for two days 
in the year. 

If we assume 2 lbs. of corn or its equivalent to be 
the average amount of nutriment required by an indi' 
vidual, this makes 730 lbs. annually. According to 
the supposition made above, 36 million pounds of am- 
monia would produce thirteen times as much = 468 
million pounds of corn or its equivalent, whereby 641,- 

000 individuals could be nourished for a year. 
Supposing the population of England and Wales to 

increase only 1 per cent, annually, this makes 200,000 
individuals in one year, and 600,000 in three years. 
JSTow the cereals hypothetically raised by help of the 
ammonia in 6 million cwt. of guano imported from 
abroad, would suffice but very few years to support the 
increased population of England and Wales. 

And wdiat would 1)6 the state of things six or nine 
years afterwards in England or Europe, if we were 
actually dependent ujDon a foreign importation of am- 
monia, for the support of the increasing population ? 
Could we import 12 million cwt. of guano in six years, 
or 18 million in nine years ? 

We know most positively, that in a few years the 
source of ammonia in guano will be exhausted ; that 
we have no prospect of discovering a new and richer 
source ; that the annual increase of population, not only 
in England but in all European countries, is more than 

1 per cent. ; and, hnally, that in proportion to the in- 
crease in the population in the United States, Hungary, 
&c., a corresponding diminution must follow in the ex- 
portation of corn from those countries. From these 
considerations the hope of augmenting the crops of a 



COST OF AMMONIA. 307 

country by the importation of ammonia must aj^pcar 
utterly vain. 

In Germany, a pound of Avlieat costs at present 4 
kreutzers [l-hl.) ; a pound of sulphate of ammonia, 9 
kreutzers (3M.) ; and if it were possible with a ])Ound 
of this salt, added to our ordinary manures, to produce 
2 pounds more of wheat, then for every outlay of one 
florin {2s.) in money, the German fanner would receive 
53 kreutzers {Is. 9d.) in corn. This relation of outlay 
.to income is evidently well known in practice, for up to 
this moment salts of ammonia have nowhere come into 
general use ; and though many manufacturers of ma- 
nure add a certain quantity of ammonia to their produc- 
tions, this is chiefly to humour the fancy of farmers for 
this substance ; but none of them can tell what advan- 
tage results from this addition. This prejudice will 
soon disappear of itself, when farmers have learned to 
make a proper use of the nitrogenous food which nature 
supplies spontaneously to the land without any aid on 
their part. 

The abundant supply of nitrogenous food in the 
soil, the increase of the same in well-cultivated ground, 
the examination of rain-water and of the atmosphere, 
all facts observed in cultivation in general, prove that, 
even with the highest system of farming, the soil is not 
exhausted in its store of nitrogenous food, and that con- 
sequently there is a circulation of nitrogen, like that of 
carbon, which presents to the farmer the possibility of 
increasing his store of active nitrogen in the soil. 

The extraordinary eftect of superphosphate of lime 
in augmenting the cro])S of corn, turnips, and clover, 
almost without exception, upon all German lands to 
which these non-azotised manures have been a])])lied ; 
the operation of the newly-introduced Baker and Jarvis 
guanos* (which contain no anmionia) ; the action of 
lime, salts of potash, gypsum, (fee., all show without 
doubt that an accunndation of nitrogenous food has 
taken place in the soil, the source of which was, until 
lately, quite obscure. 

* From a communication in tlie ' Official Gazette,' No. 3, of 1st Marcb, 



308 AMMONIA AND NITRIC ACID. 

We had reason enough to believe in a partial resto- 
ration to the soil of nitrogenous food by air and rain, 
but that it should be augmented was quite unexplained ; 
because this presupposed that ammonia and nitric acid 
were produced from the nitrogen of the atmosphere, in 
evidence of which we had no facts whatever Very 
recently this source of the increase of the nitrogenous 
food of plants was discovered by Schonbein, and the 
problem was solved in the most unexpected manner. 

In his experiments upon oxygen, Schonbein found 
that the white fume emitted by a piece of moist phos- 
phorus is not, as was previously believed, phosphoric 
acid, but nitrate of ammonia. 1 myself had an oppor- 
tunity of seeing this proved at a lecture, illustrated by 
experiments, which Schonbein delivered at Munich in 
the summer of 1860. It is probable, as he states, that 
in this reaction the nitrogen of the atmosphere, by a 
kind of induction, combines with three equivalents 
of water, whereby on the one hand nitrous acid, and 
on the other ammonia, are formed ; just as is well 
knoM'n that under the influence of a higher tempera- 
ture, nitrite of ammonia is decomposed into water and 
nitrogen gas. The most striking fact is, this salt is 
formed under circumstances which we should have been 
led to suppose were precisely those opposed to its for- 
mation ; but the production of the peroxide of hydrogen 
(so easily decomposed by heat), during the slow oxida- 
tion of sether, which is attended by a perceptible evolu- 
tion of heat, is a fact not less certain, and hitherto 
equally unexplained. 

The formation of nitrite of ammonia during this slow 
process of oxidation made it j)robable that it takes place 
everywhere on the earth's surface where oxygen enters 

1862, for the Agric. Union in Saxony, the following crops per acre were 
obtained in 1861 : — 

Wheat. 

^ 1^ ^ 

Corn. Straw. 

3 cwt. Jarvis guano producecT 2244 lbs. 4273 Iba 

3 " Baker " " 2929 " 5022 " 

6 " steamed bones " 3015 " 4755 " 

Unmanured " 1955 " 3702 " 



FOKMATION OF NITRITE OF AilMONIA. 309 

into combination ; and consequently that the same pro- 
cess, whereby carbon is converted into carbonic acid, 
forms also an ever-renewing source of nitrogenous food 
for plants. 

Soon afterwards, Kolbe showed (' Annal. d. Cheui. 
u. Pharm.' bd. 119, s. ITG) that if a flame of hydrogen 
gas is allowed to burn in the open neck of a flask con- 
taining oxygen, the interior is tilled with the red fumes 
of nitrous acid.'- 

Further, Boussingault observed that, in the con- 
sumption of common illuminating gas, the water in 
Lenoir's gas machine contained ammonia and nitric 
acid ; and shortly after, BiJttger mentioned, in the 
' Annual Report of the Physical Society of Frankfort ' 
(meeting of Nov, 2, 1861), that, according to his experi- 
ments, not only in the case of hydrogen, but generally 
when hydro-carbons were burned, a certain quantity of 
nitrite of ammonia was always formed, together with 
water and carbonic acid. Almost contemporaneously 
with this notice, I received from Schonbein a written 
communication announcing the very same results which 
he had obtained in the same M'ay, so that no doubt can 
remain as to the correctness of this fact. 

The practical ftirnier, who is really anxious to im- 
prove his method of cultivation, must be led by these 
undoubted facts to determine upon ascertaining, with 
the greatest clearness, the eft'ect of nitrogen in his ma- 
nures. Before he has been convinced that the atmos- 
phere and rain convey the necessary amount of nitro- 
genous food to his plants, no one could expect him to 
renounce the employment of ammonia as a manure. 
When it is asserted tliat a farmer can give a maxi- 
mum of fertility to his land without supplying to it any 
nitrogenous matter, it is not meant that he must re- 
nounce the use of farm-yard manure ; but the assertion 
implies the existence of the latter, and is, in fact, based 
upon it. 

For the restoration or augmentation of productive 

'^ The formation of nitrous acid in cuJiometrical cxperlmenta wag 
already known. 



310 AMMONIA AND NITRIC ACID. 

power in exhausted corn-fields, it is absolutely necessary 
that the arable soil should contain a surplus of all nutri- 
tive substances for cereal plants, nitrogenous among 
others, but no one in greater proportion than the rest. 
It is assumed that the farmer by a right succession of 
crops, that is, by a proper proportion between his corn 
and fodder fields, is always in a position, by carefully 
husbanding the ammonia in his farm-yard inanure and 
avoiding all unnecessary waste, to provide the arable 
soil with such a surplus of nitrogenous food as will cor- 
respond to the proportion of the other nutritive sub- 
stances therein stored ; and that the atmosphere annu- 
• ally makes up what he removes in his crops. 

The nitrogenous food conveyed by the atmosphere 
and rain, is upon the whole sufficient for his cultivated 
plants, but not enough for many of them in point of 
time. In order to give a maximuui crop, many plants 
require;, during the period of vegetation, much more 
than the air and rain atford in that time ; and therefore 
the farmer makes use of fodder plants in order to in- 
crease the crops of his corn-fielcls. The fodder plants, 
which thrive without rich nitrogenous manure, collect 
from tlie ground and condense from the atmosphere, in 
the form of blood and flesh constituents, the ammonia 
which is supplied from these sources ; and the farmer, 
in feeding his horses, sheep, and cattle with the turnips, 
clover, &c., receives, in their solid and fluid excrements, 
the nitrogen of tlie fodder in the form of ammonia and 
products rich in nitrogen ; and thus he obtains a supply 
of nitrogenous manures or nitrogen, wdiich he gives to 
his corn-fields. 

The rule is, that for certain plants, weak in devel- 
opement of leaf and root, and which have but a short 
period of vegetation, the farmer must compensate by 
the quantity of manure for the time which is icanting 
for the absorption of the recpiisite amount of nitrogen 
from natural sources. 

It is easy to see that tlie accumulation of nitro- 
genous food by farm-yard manure in the uppermost 
layers of the ground, so very important for the perfect 



GREAT DIVERSTTY IN NATURE OF SOILS. 



311 



growth of cereal plants, must oliiefly depend npon the 
successful growth of fodder plants. 

The luimanured fields in the Saxon experiments — 





Yielded 
altogether. 

Nitrogen. 


Lost by- 
sale of crop. 

Nitrogen. 


Eeceived 

in farm-yjird 

lUiinure. 

Nitrogen. 


Clover 
crops. 


1851-1854. 


lbs. 

342 4 
279-5 
IGOJ) 
127-7 


lbs. 

78-4 
841 
54-8 
57-2 


lbs. 

2636 

175-0 

1061 

70-5 


lbs. 
9144 




5538 




1095 


Obcrbobritzsch 


911 



It is easily perceived from this table that the quanti- 
ties of nitrogen which could be obtained from the field 
and restored in the form of farm-yard manure, bear a 
proportion not exact but sufficiently well marked, to 
the crops of clover produced by the field ; and there 
can be no doubt that the farmer who takes the right 
way to make his fodder plants thrive, obtains at the 
same time the means of enriching his arable soil with a 
surplus of nitrogenous food for his corn-plants. 

We do not mean to imply that in every possible case 
the farmer must renounce the idea of supplying to his 
land ammonia from other quarters ; for soils vary so- 
very much in their nature, that even though we can 
assert that by tar the greater proportion of them may 
not require a restoration of nitrogenous food, yet this 
will not hold good for all without exception. In a soil 
rich in lime and humous materials, in consequence of 
the process of decay going on, a certain quantity of the 
ammonia fixed in the earth is converted into nitric acid, 
which is not retained by the soil, but is conveyed into 
the lov/er layers in the form of salts of lime or mag- 
nesia. Under certain circumstances, this loss may 
amount to much more than is compensated by the at- 
mosphere, and for such fields a snp})ly of ammonia will 
always be useful. The same holds good for certain soils 
which have not been tilled for many years, and in 



812 AMMONIA AND NITfllC ACID. 

whicli, by tlie operation of the causes above-mentioned, 
the necessary surplus of nitrogenous food, formerly 
present, is gradually expended. On recommencing the 
cultivation of such soils, the employment of nitrogenous 
manures will at first produce a remarkably beneficial 
effect. Afterwards, these too require no further supply. 

There is one reason which excites in the farmer's 
mind a prejudice in favour of introgenous manure, and 
that is the great inequality in the appearance of the 
young crops, when such manures are applied in com- 
parative experiments. The cereal plants upon fields 
manured with guano or nitrate of soda are distinguished 
before others by a deep green colour, and by broader 
and more numerous leaves ; but the harvest is generally 
far from corresponding to the expectations raised by 
this promising appearance. Upon a field excessively 
rich in nitrogenous food, there is a kind of rankness in 
the early growth like that produced by a hot-bed : the 
leaves and stalks are watery and weak, in consequence 
of the want of time in their over-hasty growth to absorb 
contemporaneously from the soil the necessary quantity 
of substances, such as silicic acid and lime, capable of 
communicating to their organs a certain solidity and 
power of resistance against those external causes which 
endanger their existence. The stalks fail to acquire the 
necessary stiffness and strength, and are always liable 
to be laid, especially on lime soils. 

This injurious influence of excess of nitrogenous food 
is particularly remarkable in the case of the potato 
plant ; for if it grows upon a soil excessively rich in 
nitrogenous food, and the temperature should suddenly 
fall and wet weather supervene, the plant is often at- 
tacked by the so-called potato disease ; while a neigh- 
bouring potato field merely manured with ashes shows 
no trace of it. 

Among all the many experiments which have been 
hitherto made by farmers to improve their land, there is 
not one instituted for the purpose of ascertaining the 
actual condition of their soil, or of seeking proofs for 
the correctness of the notions which they had once 



PEACTICAL FARMER GUIDED BY FACTS. 313 

adopted. Tlio reason of their indifference about ol)tain- 
ini>" jiroots for their views ehieliy consists in tliis, that 
the practical man, like the artisan, is guided in his busi- 
ness not bj ideas, but by facts. Hence it is quite in- 
different to him, whether the theory, or "what he dig- 
nifies by that name, is correct or not, as he does not 
regulate his proceedings in accordance with it. 

Many thousand farmers, wlio have not the remotest 
conception of the nutrition of plants or the composition 
of manures, apply guano, bone earth, and other ma- 
nm*es, to their fields, with fully the same effect and 
with even the same skill as others who possess such in- 
formation ; nor do the latter derive any manifest ad- 
vantage from their knowledge, because it is not of the 
right kind ; for example, the chemical analysis of ma- 
nures is rather calculated lor ascertaining their purity, 
and for determining their price, than as a means for 
making us acquainted with their effect upon land. 

In England bone earth was used and valued as a 
manure half a century before any idea was formed as to 
what its operation was due ; and when afterwards the 
erroneous theory was adopted that its effect depended 
upon the nitrogenous gelatine which it contained, this 
view did not exert the slightest influence upon its em- 
ployment. 

The farmer manured his field with bone earth, not 
on account of its nitrogen, but because he wished to 
have larger crops of corn and foddei", and because ex- 
perience told him that he could not expect them with- 
out bone earth. 

An agricultural practice, founded upon a simple ac- 
quaintance with facts, without any idea of their nature, 
or one based on the exhaustion of the land, may be con- 
ducted by a person of very limited intelligence, nay, 
the most ignorant man may be fitted for the purpose, 
by the mere statement of facts to him. But a rational 
pursuit of agriculture, which, with the greatest economy 
of capital and labour, can obtain from a field continu- 
ously without exhaustion the highest crops it is capable 
of yielding, requires a large compass of knowledge, 

14 



314 AMMONIA AJSID NITRIC ACID. 

observation, and experience, more perhaps than in any- 
other business. For the rational agriculturist must not 
merely know all the facts with which the illiterate peas- 
ant is acquainted, but he must also be able to appre- 
ciate them at their proper value ; he must know the 
reason of all his proceedings, and what efiect they may 
have upon his land. He must be able to interpret what 
his field tells him in the phenomena which he observes 
in practice ; in a word, he must be a thorough man, 
and not a half-and-half creature who knows no more 
about his actions than a tom-cat, with just skill enough 
to catch gold fish in a basin of water.* 

* If we compare the theoretical views expressed in the works of con- 
fessedly good practical farmers with the system of husbandry which they 
have found by their own experience to be the best, we observe the most 
irreconcilable contradictions between the two. 

Walz (' Communications from Hohenheim,' No. 3, 185*7) disputes both 
these propositions, viz. : — 

' That the removal of the mineral constituents in the crops, tvithout 
compensation, produces sooner or later lasting unfruitfulness as a conse- 
quence.' 

' That if a soil is to maintain its fertility contimioitsh/, the removed 
mineral constituents must, sooner or later, be returned to it, i.e. the com- 
position of the soil must be restored.' 

And gives as his opinion that both these propositions are at present appli- 
cable only to soils of the worst kind, Avhich needed a supply of mineral 
matters from the very beginning. 

Now, if we turn to the 'Application of his theory to practice' (page 
117), we would naturally suppose that he would never trouble himself 
about any compensation ; but it soon appears that he is far from believing 
in the truth of his own doctrines. He lays the proper stress upon the 
restoration of potash, lime, magnesia, phosphoric acid, gypsum, guano, 
bone-earth, marl, and farm-yard manure ; and lays down the following 
rule: — ' Tliat the fai-mer, to keep his ground in uniformly increasing fer- 
tility, must not remove more in his crops than the products of the atmos- 
phere and the assimilable mineral substances added annually to the soil 
by the action of the weather.' He says further : — ' If the farmer were to 
confine his business entirelj', e.g. to the manufacture of beer, spirit, sugar, 
darch-meal, dextrine, vinegar, &c., and the sale of animal products merely 
to butter, using up the skimmed milk ; if for his dairy he were to buy none 
but full-grown cows and not breed them himself, thus endeavouring to 
keep the phosphates upon his farm, then he would not 0!ily preserve con- 
tinually the mineral substances in his store of manure, but he would also 
increase them by the yearly process of disintegration, unless he preferred 
to alienate the latter in his produce' (s. 142). 

Hence the point of his practical teaching, in direct opposition to his 



A RATIONAL AGRICULTURIST. 315 

theoretical, is tliiit, in order to obtain uniform crops, great care must be 
taken to maintain and restore the coniposilion of the soil. 

The practical man proves that the notions which he has conceived are 
entirely inapplicable in his jiractice ; and that the scientific i)rinciples 
which he disputes are precisely those by which he is unconsciously j^uided.. 
Sound practice and true science are ever in unison ; and a contest on these 
matters is possible only between two persons, one of whom does not under- 
Ktund the other. The chief fault lies in want of precision in defining 
things, and in using indefinite or vague language to express our ideas. 

The opinion of Rosenberg-Lipinsky (see his ' Practical Agriculture,' 
b. ii. Breslau: E. Trewends, 1862), is 'that no kind of plant actually 
exhausts the great storehouse of the soil' (p. 738); and further, 'that 
plants, directly and indirectly, return to the soil more strength than they 
take from it' (p. 740). This opinion is thus modified (j). 742): — ' when 
therefore the farmer does not take sufficient care that the more important 
magazine of nutriment, the soil, receives at the right time, and in proper 
quantity, the necessary compensation for that which is inevitably consumed, 
the picture of exhaustion which the cultivated plants manifestly wear, 
cannot possibly be charged upon their consumers, but the blame is wholly 
and solely attributable to the farmer himself Further, at p. 740, he .says, 
' Only in those plains, where the injustice of the elements, or of man, has 
violently disturbed the natural laws of the nutrition of plants, does the 
scanty vegetation of the wild flora indicate the exhaustion of the soil.' 



CHAPTER XII 



COMMON SALT, NITRATE OF SODA, SALTS OF AMMONIA, 



GYPSUM, LIME 



Effect of these substances as elements of food , their effect on the condition of the 
Boil — Kulilmann's experiments with common salt, nitrate of soda, and salts of 
ammonia ; experiments with the same substances in Bavaria ; conclusions : 
those matters are. elements of food ; they are chemical means for preparing tlio 
soil ; they cause the distribution of the food in the soil in the form proper for 
the growth of plants — Experiments by Pincus with gypsum and sulphate of 
magnesia on clover; decrease of flowers and increase of stem and leaves of 
clover by sulphates ; the crop is not in proportion to the quantity of sulphates 
used— Effect of gypsum not yet explained ; indication in the comportment of 
clover soils with solution of gypsum ; such solution disperses potash and 
magnesia in the soil — Manures, their effect not explained by the composition of 
plants produced by them — Composition of the ash of clover manured with dif- 
ferent substances — Effect of lime ; experiments of Kuhlmann and Triiger ; 
comportment of lime-water with soils. 

THESE salts are employed in agriculture in many 
cases with marked success as manure ; and since 
nitric acid, soda, ammonia, sulphuric acid, and lime, 
are nutritive substances, the explanation of their efficacy 
presents no difficulty. But they also possess other 
peculiarities, by which they aid and promote the action 
of the plough and of mechanical tillage, as well as the 
influence of the atmosphere upon tlie condition of the 
field. This influence is not always clear to our minds, 
but it is not less certain. 

We have every reason to believe that where the 
crops are increased by manuring with common salt 
alone, or when the favourable influence of salts of am- 
monia or nitrate of soda is augmented by tlie additjon 
of common salt, the operation of the three salts essen- 
tially depends upon their power of diffusing the nutri- 
tive substances present in the soil, or of preparing those 
substances for absorption. In what manner this takes 
place with all is not yet explained. The first trust- 



COMMON SALT WITH SALTS OF AMMONIA. 



317 



wortliy experiments in this direction were made by F. 
Iviihlmann (' Annul de Cliim,' 3 ser. t. xx., p. 279). In 
the year 1845 he manured a natural meadow with sal 
ammoniac, sulphate of ammonia, and common salt ; 
and obtained the following quantities of hay : — 

Cro}^ of luiij 2>(">' hectare, 1845 and 1846. 

Increased crop. 

Unmanurcci 11263 kilos. — 

Sal ammoniac, yearly 200 kilos 14964 " 3700 kilos. 

" " 200 " ) 

Common salt " 200 " \ 



.16950 



5687 



Another meadow yielded : — 

Croiy of hay, j^^r hectare, 1846. 



Unmanurcd 3323 kilos. 

Sulphate of ammonia 200 kilos 5856 " 

" 200 " ) 
Common salt 133 " f 



6496 



Increased crop. 

2533 kilos. 
3173 " 



For the purpose of examining the effect of common 
salt upon cereals, the General Committee of the Agri- 
cultural Society in Bavaria instituted at Bogenhausen 
and "VVeihenstephan, in the years 1857 and 1858, a series 
of experiments, conducted thus : of two plots, the one 
was manured with salts of ammonia, the other with the 
same quantity of salts of ammonia and an addition of 
3080 grammes of common salt. These experiments 
were described at page 286, and it will be sufficient 
here to quote the crops which were obtained with salts 
of ammonia alone, and with common salt added to salts 
of ammonia. 

Bogenhansen, 1857. 





Manured with 
salts of ammonia. 


Manured with common salt 
and salts of ammonia. 


B.irley. 


Corn. 


StVaw. 


Corn. 1 straw. 


riot I 

" 11 

'* III 

"IV 


Grammes. 
6355 
8470 
7280 
6912 


Grammes. 
16205 
16730 
17920 
18287 


Grammes. 

14550 

16510 

9887 

11130 


Grammes. 
27020 
36645 
24832 
27969 



318 SALT, NITKATE OF SODA, SALTS OF AMMONIA, ETC. 

Bogenhausen, 1858 (p. 287). 





Manured with 
saltB of ammonia. 


Manured with common salt 
and salts of ammonia. 


Winter-wheat. 


Corn. 


Straw. 


Corn. 


Straw. 


Plot I 

" II 

" III 

"IV 


grammes. 
19600 
21520 
25040 
27090 


grammes. 
41440 
38940 
57860 
65100 


grammes. 
29904 
31696 
31416 
34832 


grammes. 
61040 
71960 
74984 
74684 



In botli these series of experiments, the crops of 
corn and straw were remarkably increased by the addi- 
tion of common salt ; and it is scarcely necessary to 
repeat, that such an augmentation could not possibly 
have taken place unless the soil had contained a certain 
quantity of phosphoric acid, silicic acid, potash, &c., 
capable of being brought into operation, but which 
without common salt was not assimilable. 

Similar experiments were undertaken by the same 
society in Weihenstephan with nitrates ; and the crops 
produced by these salts alone, and with the addition of 
common salt, per hectare, were as follows : — 

Weihensle2)han, 1857. — Summer barley. 



1857. 

Summer-barley. 

Quantity of ma 

nure 

AJ Corn 

^\ Straw 

1S58. 

Winter- wheat, 
(the same 
manures.) 

•rj 1 Corn 

^ \ Straw 



1604 
2580 



1699 
3030 



2676 
4378 



1804 
3954 



Nitrate of 

soda nith 

coaimoDsalt. 



kilos 



2366 
4352 



2211 
4151 



Nitrate of 
potasti. 



kilos. 



473 

2064 
4219 



2248 
44C4 



Nitrate of 
potash with 
commousalt. 



kilos. 



473-1-1379 

2313 

4766 



2323 
4454 



VI. 
Guano. 



1922 
3300 



2366 
5091 



The experiments are remarkable in so far as they 
appear to indicate the cases in which the nitrates alone, 



EFFECT OF COMMON SALT. 319 

or in combination with common salt, exert a favoui'able 
influence upon the increase of the crops. 

The hiiid in "Weihenstephan is peculiarly suited for 
the cultivation of barley. Field A, after a manuring 
of the ordinary kind, about GOO cwt. per hectare, had 
borne turnips in 1854, peas in 1855, and wheat in 185G ; 
it was then intended to let it lie fallow for one year, 
and to dress it at the end of the year for a new crop. 
On the other hand, Field B, before the experiment was 
made, had already borne four crops, namely, rape, 
wheat, clover gi'ass, and oats ; and was, in comparison 
with the first held, more exhausted, and by means of 
the oats and clover made much poorer in nutritive sub- 
stances for the following cereal crop. 

This seems to afford an explanation of the striking 
fact, that in 1857 the nitrates exercised upon the field 
a far more favourable influence than guano, although 
tlie soil had received as much nitrogen in the guano as 
in the nitrates, with the addition of phosphoric acid 
and potash. The field wa» still rich enough in nutri- 
tive substances for a good barley crop, and merely 
required their more uniform distribution (which was 
efiected by the nitrates and the common salt), in order 
to make available to the roots of the barley plants as 
much or even more food than was the case with the 
plot manured with guano, on which the sum of the nutri- 
tive substances was greater. 

In estimating the results of these experiments we 
must take into account the fact established by Dr. 
Zoeller, that soda seems to take a definite part in the 
production of barley seed. It is clear that the nitrates 
used did not simply act as agents in distributing other 
nutritive substances, but the soda as well as the nitric 
acid had their own share in the production of the crop. 
In the fourth experiment the field received as much 
nitric acid as in the second, but the base combined 
with the acid was potash and not soda ; and in the 
fifth experiment the addition of common salt produced 
a remarkable increase in the corn crop. However, in 
the third and fifth experiments the quantity of salt ap- 



320 SALT, NITRATE OF SODA, SALTS OF AMMONIA, ETC. 

plied was evidently too Iiigli, and the excess brought 
down the cro]) below that obtained with nitrate of soda 
alone, 

Ujion the more exhausted field in 185S the crop 
obtained by guano in corn and especially in straw ex- 
ceeded all the rest. In the arable soil of this field the 
amount of nutritive substances was on the whole smaller, 
and the addition of fresh elements of food made itself 
felt in a much higher degree than the distribution or 
dissemination of the substances already present in the 
soil. Still by tlie addition of common salt the crop of 
wheat was also increased. 

The eft'ect of potash upon wheat is as striking as 
that of soda upon barley. 

As regards the effect of common salt and salts of 
soda generally, the analysis of the ash of turnips and 
potatoes, kitchen-garden and meadow i)lants, shows 
that, as a rule, the ashes of the former contain a con- 
siderable quantity of soda, and the ashes of the latter 
are proportionately rich in chlorides. The grass of a 
meadow, which has been manured with common salt, 
is eaten by cattle with greater relish, and preferred to 
any other, so that even from this point of view com- 
mon salt deserves attention as a manure. 

As that part of the action of nitrate of soda, sea-salt, 
and salts of ammonia, which consists in effecting the 
distribution hi the soil of other elements of food, may 
consequently be replaced by careful tillage, the effect 
produced upon the crops by these salts affords a pretty 
safe indication of the condition of a field. If all other 
circumstances are the same, their eftect will be much 
less marked upon a well tilled field than upon one not 
in the same condition. 

Gypsum. — Among the recent investigations respect- 
ing the action of gypsum on clover,* those made by Dr. 

* That excellent and most ably conducted agricultural journal, 
' Zeitschrift des landwirthschaftlichen Vereins fiir Rhein. Preussen,' con- 
tains, in Nos. 9 and 10, September and October 1861, p. 352, the follow- 
ing statement about the remarkable fertility of a field for clover : — 

' Twenty-three years ago Farmer Kirfield, of Rhon, in the hundred of 



ACTION OF GYPSUM gIT CLOVER. 321 

Pincus, of Insterbnrg, are tlie most important, both on 
account of the careful manner in which they were con- 
clueted, and tlie conclusions drawn from them. At Dr. 
Pincus' request, three plots of ground, each of a morgen 
(about f of an acre) in extent, and lying close together, 
were selected by Mr. Koscnfeld in the beginning of 
May, from the middle of a large clover held in the 
neighbourhood of Lenkeningken. The clover crop had 
a very promisin ;; appearance, and the plants were then 
about an inch high. One of the plots was manured 
with a cwt. of gyjisum, the second with the same quan- 
tity of sulphate of magnesia, and the intervening plant 
was left unmanured. The clover field from which the 
plots were selected was one of the best cultivated and 
most fertile in the district, and had produced in the 
preceding summer an abundant rye crop. The plants 
growing on the unmanured plot, when compared with 
those on the manured, very speedily presented a differ- 
ence of colour and condition. 

On the plot manured with gypsum, they were of a 
deeper green, and stood higher. The difference was 
most striking at the time of flowering, which occurred 
in the unmanured plots four or five days earlier than 
in the manured ; the whole field being everywhere in 
full bloom, when scarcely a flower was to be seen in 
the manured plots. When the manured plots also were 

Antweiler, Aldenau district (volcanic Eifel mountains), sowed a plot of 
land, said to abound in broken shells, with esparsette. For ten years he 
obtained good hay crops, and abundant after-grass. After this time a good 
deal of grass began to make its appearance among the esparsette. To 
destroy this Mr. Kirfield had his field deeply harrowed in spring, with iron 
harrows across the ridges, and then sown over again with 8 pounds of red 
clover seed. The red clover grew up splendidly with the esparsette, and 
gave for three years running two full crops per annum. At the end of the 
third year the land was again deeply harrowed and sown anew with 8 
pounds of red clover seed. It gave again for three years running two full 
crops per annum of an excellent mixture of espai-sctte and red clover. 
The same operation was repeated twice after with the same success, so 
that the field has now for twenty-two years, consecutively, borne clover ; 
that is to say, the first ten years esparsette alone, the following twelve 
ytiars cspai-sette with red clover.' 

It would be interesting to get a proper analysis of this soil, with especial 
regard to its absorptive power for potash and phosphate of lime. 
14* 



322 SALT, NITKATE Of SODA, SALTS OF AMMONIA, ETC. 

in flower the clover was mown (May 24th). A square 
ruthe was measured from each of the experimental plots, 
and the clover separately cut and weighed. 

Calculated per Prussian morgen ( = f of an acre), 
the results were, — 

Cwts. of clover-hay 
per morgen . 

Without manure 2r6 cwts. 

With gypsum 80-6 " 

With sulpliate of magnesia 32'4 " 

On a closer examination of the clover-hay it was 
found that the increase in the crops obtained from the 
plots manured with the sulphates did not extend equally 
to all parts of the plant, but was more particularly ob- 
servable in the production of stems. There were found 
in 100 parts of the clover from the manured plots more 
stems, fewer leaves, and still fewer flowers, than in 100 
parts of the unmanured clover. 

Manured Manru-ed 
Unmanured. with with sulphate 
gypsum, of magnesia. 

100 parts of clover-hay, flowers IT'IS 11-72 12-16 

" leaves 2'7-45 26-22 25-28 

" stems 55-40 61-62 63-0 

or. 

Flowers. Leaves. Stems. 

Clover-hay, unmanured 17*15 27*45 55-40 

" manured with gypsum 11-72 25-28 63-0 

" " sulphate of 

magnesia 12-16 26-22 61-62 

These proportions of the difierent organs of the 
clover plant show that the action of the sulphates has 
led to a very considerable increase of the wood-cells, 
or, in other words, to an extension of the stems at the 
expense of the flowers and leaves. The relative propor- 
tion of the flowers, leaves, and stems, was : — 

Flowers. Leaves. Stem.a. 

Clover-hay, unmanured 100 : 160 : 823 

" manured with gypsum 100 : 216 : 507 
" " sulphate of 

magnesia 100 : 216 : 538 

According to the law of the symmetrical develope- 
ment of plants, we may, without risk of error, take it 



EFFECT OF GYPSUM ON CLOVEK. 323 

for granted tliat the develop einent of tlic root increased 
in the same ratio as that of the stem. Now, as the in- 
crease of a plant in bulk is proportionate to the extent 
of food absorbent surface, we can understand that the 
manured plots should have produced when compared 
with the uniiianured not only a larger mass of stems, 
but, as in the case of the sulpliatc of magnesia plot, 
also of llowcrs and leaves. 

The entire crop per morgen, was, — 

Manured Manured with 
Unmanured. with sulphate of 

gj'psum. magnesia. 

Flowers S'TOo lbs. 358-5 lbs. 394-0 lbs. 

Leaves 592-0 " 773-7 " 849-5 " 

Stems 1196-6 •' 1927-8 " 1996-5 " 

2160 " 3060 " 3240 " 

The cpiantity of most of the ash constituents was 
found larger, nearly in the same proportion as the pro- 
duce was greater. Phosphoric and sulphuric acids, 
however, showed in this respect a marked difference 
from the other ash-constituents, inasmuch as the quan- 
tity of these two substances was both absolutely and 
relatively larger in the clover from the manured plots. 

The ash of the air-dried clover-hay amounted to — 

Manured Manured with 

Unmanured. with pulpliato of 

gypsum. niaenecia. 

Percent 695 7-96 7-94 

In the entire crop 150-0 lbs. 243-0 lbs. 257-0 lbs. 

Containing sulphuric acid 2-0 " 8-0 " 6-0 " 

phosphoric acid ... 11-95" 21-55" 21-82" 

The dressing with the sulphates had checked the 
developement of the flowers, and also that of the fruit ; 
and it is evident that, though a higher crop of stems 
and leaves may be obtained by the use of these agents 
from a given surface, the result is not the same as re- 
gards the seeds. AVith an increase of flowers, leaves, 
and stems in the same ratio as on the unmanured plot, 
the two morgens of ground, dressed severally with 
gypsum and sulphate of magnesia, ought to have ])ro- 
duced more than 000 11'S. of flowers each ; whereas, 



324 SALT, NITRATE OF SODA, SALTS OF AMMONIA, ETC. 

compared witli tlie enormous increase in the weight of 
the stems, and a not inconsiderable one in the weight 
of the leaves, we find no increase of flowers, and con- 
sequently also none of seed (Pincus). These most care- 
fully conducted experiments confirm the general rule, 
that wherever external causes favour the developement 
of some organs, it can only be efi'ected under like con- 
ditions of the soil, at the expense of other organs, and 
that in the case of clover, as in that of the cereals, in- 
crease of straw is attended with decrease of seed. (For 
farther details of these experiments, see Appendix J.) 

As the substitution of magnesia for lime, in the ex- 
periments now described, led to an increase of the 
clover crop, it may be safely assumed that in cases 
Vv'here gypsum is found to be favourable to the growth 
of clover, the cause must not be sought for in the lime, 
although it is very often found that many fields will 
grow clover onl}^ after a copious dressing with hydrate' 
of lime. For we know also that gypsum promotes the 
growth of clover on many fields naturally abundant in 
lime ; and since arable soil has the property of absorb- 
ing ammonia from the air and rain-water, and fixing it 
in the same or even a higher degree than salts of lime, 
there is only the sulphuric acid left to look to for an 
explanation of the favourable action of gypsum upon 
the growth of clover. 

Bat the experiments of Pincus clearly demonstrate 
that the crops obtained by manuring with the sulphates 
bear no proportion whatever to the quantity of sul- 
phuric acid supplied in them to the field. 

The quantities of sulphuric acid severally contained 
in the two sulphates used were 30"12 lbs. in the sul- 
phate of magnesia, and 4-i*18 lbs. in the sulphate of 
lime, which is as 6 : 8*8. The quantities of sulphuric 
acid in the two crops obtained severally by sulphate 
of lime and sulphate of magnesia, were as 6 : 8 ; the 
ash of the clover produced by sulphate of lime con- 
tained a little more than 8 lbs., and that from the sul- 
phate of magnesia 6 lbs. On the plot dressed with 
gypsum the clover plant found a larger total quantity 



ACTION OF GYPSUM ON CLOVER NOT KNOWN. 325 

of sulphuric acid than on the sulphate of magnesia plot, 
and absorl)ed a correspondingly larger proportion. But 
this additional quantity of sulphuric acid absorbed did 
not increase the amount of produce ; on the contrary, 
on the plot manured with sulphate of magnesia, which 
had received less sulphuric acid than the gypsum plot, 
the amount of vegetable matter was 8 per cent, higher 
than on the latter. 

These facts show that we arc still in the dark about 
the action of gypsum ; and it will yet require a great 
many and most accurate observations before we are 
likely to arrive at a satisfactory explanation. 

So long as the notion was generally entertained that 
plants derived their food from a solution, the efiects of 
a soluble salt upon vegetation could, of course, be at- 
tributed only to the constituents of that salt. But now 
we are aware that the earth itself performs a special part 
in all the processes of nutrition ; and there might, there- 
fore, be grounds for supposing that the action of gypsum 
upon arable earth, or of the latter upon the former, 
might furnish a key, to some degree at least, to explain 
the effect of gypsum upon the growth of clover, A 
series of experiments made by me upon the alterations 
which a saturated solution of gypsum in water under- 
goes in contact with different arable soils, give very 
remarkable results, whch I will now state, without 
venturing to draw any definite conclusions from them, 

I found that a solution of gypsum in contact with 
all the arable soils which I used, underwent decompo- 
sition, part of the lime separating from the sul})huric 
acid, and magnesia and ])otash taking its place, quite 
contrary to the ordinary affinities. 

The experiments were made as follows : — 300 
grammes of each earth were mixed with a litre of pure 
water, and 300 other grammes of the same earth Avith 
a litre of a saturated solution of gypsum. After twenty- 
four hours the fluid was filtered, and the filtrate tested 
for magnesia. Pure distilled water took up from all 
the experimental earths, sulphuric acid and chlorine, 
besides traces of lime, magnesia, and soda, and occa- 



326 SALT, NITRATE OF SODA, SALTS OF AMMONIA, ETC. 

sionally also of potash, but mostly in inappreciable 
quantities. The alkalies, as well as the lime and the 
magnesia, seem to be dissolved by the agency of or- 
ganic matters, as the dried residues blackened upon 
heating, and e£Pervesced with acids after ignition. 

Quantities of magnesia dissolved severally out q/" 300 (jrammes 
of earth by one litre of 

Distilled water. Gypsum water. 

MlUigr. of magnesia. Milligr. of magnesia. 

Bogenhausen earth 30-2 70-6 

Schleisshcim " 31-6 8*7 8 

Bogeuhaiisen subsoil 12-2 84'2 

Earth from Botanic Gardens 45-4 168'6 

" Bogenhausen, No. I.* 20-6 101-6 

" " No. II. 38-2 98-0 

" Schomhof 8-6 63 4 

" a cotton field, Alabama 1'9 38 

These figures show that dressing a field with sul- 
phate of lime makes the magnesia in the soil soluble 
and distributable. If the action which gypsum exer- 
cises upon the growth of clover depends really upon 
an increased supply of magnesia, this must surely be 
looked upon as one of the most curious facts known, 
since the increased supply is eftected here by the aid 
of a lime salt. An ex]Deriment, made specially for the 
purpose, showed that the contact of arable earth with 
the solution of sulphate of lime is attended by an actual 
substitution of magnesia for lime ; that is to say, a cer- 
tain quality of lime is withdrawn from the solution and 
combines with the earth, wdiilst the liberated sulphuric 
acid, which was united to the lime, withdraws from the 
earth an equivalent quantity of magnesia. In a litre 
of gypsum water w'hich had been in contact with 300 
grammes of earth from a wheat-field, there were found 
the following quantities of sulphuric acid, magnesia, and 
lime : — 

* On this field it had been expernnentally proved that dressing with 
gypsum would give a larger clover crop. No. I. had not yet been manured 
with gypsum, No. II. had. 



THE ACTION OF GYPSUM IS COMPLEX. 327 

The pure gj'puum The gypsum w;itcr which 

water had been in contact 

contained in 1 litre — with the earth— 

Sulphuric acid 1 • 1 70 grammes. T 1 8 grammes. 

Lime 0-820 " 0-736 

Magnesia — " 0-074 

Besides tlie magnesia, a certain amount of potash also 
seems to be dissolved out of the earth by aid of the 
gypsum. 

Out of 1000 grammes of earth from a wheat-field, 
there was dissolved by — 

3 htrcs of pure water. 3 litres of gypsum water. 
Potash 24-3 milligr. 43-G milligr. 

These experiments show that the action of gypsum 
is very complex, and that it promotes the distribution 
of both magnesia and potash in the ground. This much 
is certain, that gypsum exercises a chemical action upon 
the soil, which extends to any depth of it, and that in 
consecpiencc of the chemical and mechanical modifica- 
tion of the earth particles of certain nutritive elements 
become accessible to, and available for, the clover plant, 
which were not so before. 

The cause of the action of a manuring agent is usually 
sought for in the composition of the plant, but I do not 
think that this is always to be relied upon. The compo- 
sition of the seed of plants of wheat, for instance, is so 
constant, or varies so little, that it is quite impossible 
to infer from the results of the analysis of the seeds 
whether the soil on which they grow abounded or was 
deficient in phosphoi*ic acid, nitrogen, potash, &c. The 
abundance or deficiency of food in a field exercises an 
influence upon the number and weight of the seeds, 
but not upon the relative proportion of their compo- 
nent elements. Thus, for instance, Pincus found a some- 
what larger percentage of magnesia in the unmanured 
clover than in the plants manured with the sulphates ; 
but taking the magnesia of the whole crop, the quantity 
of this substance was much larger in the latter than in 
the former. 



328 SALT, NITKATE OF SODA, SALTS OF AMIMONIA, ETC. 

Amount of magnesia in — 

Ilanured Manured 

Unmanurc'd. with with sulphate 

gypsum. of magnesia. 

100 parts of ash of clover-hay 5-87 5-47 5-27 

In the whole crop 8-8 lbs. 13-29 lbs. 13-54 lbs. 

Variations in the percentage proportions of potash, 
lime, and magnesia, may be often observed in all those 
plants in which, as in the case of tobacco, the vine, and 
the clover plant, potash may be substituted for lime, 
and vice versa. But in such cases the decrease of one 
body is invariably attended by a corresponding increase 
of the other. 

Now if gypsum has the property of effecting a dis- 
tribution of the potash in the ground, and this is want- 
ing in magnesia, more potash should be contained in 
the clover manured with gypsum than with sulphate 
of magnesia. According to the analysis made bj 
Pincus, the ash of the clover-hay contained : — 

Clover Clover manured 

manured with with sulphate 

gypsum. of mairnesia. 

T . (Potash 35-37 lbs. 32-91 lbs. 

^^V^rc^^i \ume 19-17 " 20-66 " 

T ,, , , 1 Potash 85-9 " 84-6 " 

In the whole ash -I j ■ a,^ a i iro .-, n 

( Lime 46-6 ' 53 2 

These figures show that the quantity of potash is 
indeed larger, and that of lime smaller, in the crop 
produced by manuring with sulphate of lime than in 
the higher crop from sulphate of magnesia. 

In the clover-hay reaped from the latter plot, the 
deficient potash was manifestly replaced by lime, and 
in the clover-hay from the gypsum manure plot, a cer- 
tain amount of lime by potash. 

An investigation, made with much carefulness, and 
without the least bias, as this by Pincus, appears, 
among the frivolous and loosely-conducted researches 
w^ith which agriculture unfortunately abounds, like a 
green oasis in a dreary desert, and is well calculated 
to show how much real knowledge remains still to be 
gained of the processes in the soil with respect to the 
nutrition of plants. (See ' Agriculturo-chemical and 



ACTION OF LIMi:. 329 

Clicniic'ul Researches and Experiments made by Dr. 
Pincus, at the Insterburg Station for Agrieulturo- 
chemical and Physical Experiments.' Gumbinnen. 
1861.) 

Lime. — I have, unfortunately, never had an oppor- 
tunity of examining a soil on wliich a lime-dressing 
has exercised a beneficial effect, as this substance is not 
used by farmers in the neighbourhood either of Giessen 
or of Munich. The experiments made by Kuhlmann, 
on meadows, in the years 1845 and 184:6, seem to show 
that lime is principally useful in altering the condition 
of the soil ; but having no data before me as to the par- 
ticular soil on which these experiments M'cre made, I 
am unable to point out wherein this alteration consists. 

Hay crop reaped per hectare, 1845 and 1846. 

kilos. kilos. 

Meadow immanurcd 11233 — 

" manured with 300 kilos, of slaked 

lime, each jear 142(13 Increase 3000 

" manured with 500 kilos, of chalk 

each year lO/OG Decrease 556 

It may safely be taken for granted here, that if the 
lime had acted as a nutritive element in the develope- 
ment of the meadow plants, the plot manured with 
carbonate of lime ought to have given a higher, but 
assuredly in no case an inferior crop, than the unma- 
nured plot. But the very reverse is the case : the car- 
bonate of lime, which could only spread through the 
soil dissolved in carbonic acid, had an unfavourable 
efiect ; the caustic lime, on the contrary, was beneficial. 

Among the Saxon experiments already so often 
alluded to, there are two of sufficient importance to 
deserve particular mention here. One of these was 
made by Traeger, of Oberbobritzsch ; the other by 
Trager, of Friedersdorf The latter omitted to make 
a coin])arative experiment to show the difference be- 
tween the produce from a plot manured with lime, and 
that from an unmanured plot of the same size. Instead 
of the latter, therefore, I placed here by the side of the 



330 SALT, NITRATE OF SODA, SALTS OF AMMONIA, ETC. 

lime experiment, for the sake of comparison, another 
made with ground bones on a plot of the same size. 

Experiment at Oherbohritzsch. 
Lime manuring (110 cwts. quick lime). 





Produce per acre, 
unmanured. 


Produce per acre, 
manured •with lime. 




Corn. 


Straw. 


Corn. 


Straw. 


1851. Rye 

1853. Oat3 

1852. Potatoes . . 

1854. Clover-hay. 


lbs. 
1453 
1528 
9751 
911 


lbs. 
3015 
1812 


lbs. 
1812 
1Y48 
11021 
2942 


lbs. 
2320 



Experiment at Friedersdorf, 
Lime manuring (same quantity as above). 





Produce per acre, manured 


Produce 


per acre, 




with 1644 lbs. ground bones. 


manured 


with lime. 




^ 




^ 












Corn. 


Straw. 


Corn. 


Straw. 




lbs. 


lbs. 


lbs. 


lbs. 


1851. Rye 


990 


3273 


1012 


3188 


1853. Oats 


1250 


2226 


1352 


2280 


1852. Potatoes . . 


8994 


— 


12357 





1854. Clover-hay. 


4614 


— 


4438 


— 



Guano produced, in the year 1854, on the field at 
Oberbobritzsch, a higher clover crop than the lime (see 
page 266) ; but on the field at Friedersdorf it was 
smaller, 616 lbs. of guano produced, at Friedersdorf, 
2337 lbs., at Oberbobntzscli, 5044 lbs., of clover-hay. 

Experiments, in which I brought lime-water in con- 
tact with difierent samples of arable soil, have shown 
that the latter possesses a similar absorptive power for 
lime as for potash and ammonia. The earth was mixed 
with lime-water, and after remaining at rest until all 
alkaline reaction had disappeared, a fresh quantity of 
lime-water was then added, just sufiicient to cause a 
feeble but permanent alkaline reaction. 



EXPERIMEKTS -WITH LIME. 



331 



Experiments on the amount of lime taken vj) out of lime-wate-n 
by different arable soils. 



1 litre* of Bogenhausen earth took up 

1 " Schleisshcim earth 

1 " earth from Botanic Gardens 
1 " subsoil from Bogenhausea . 


grms. grains. 
2-824=43-5 
2-397 = 37 -0 
3-000=46-2 
3-288 = 50-6 
2-471 = 38-0 

2-471=38-0 
6-301 = 97-0 


grms. grams. 
2-259 = 34788 
1917 = 29521 
2400 = 36960 
2630=40502 
1976 — 30430 


1 " from the same field after bearing 

a crop of clover 

1 " of turf powder 


1976 = 30430 
5040=77616 



Lime out of lime-water. 



The investigation into tlic alterations produced in 
the earth by the absorption of lime, more especially as 
regards potash and silicic acid rendered soluble, is not 
yet terminated. 



* 1 Litre = 1 cubic decimetre = 61 cubic inches. 



APPEKDIOES. 



APPENDIX A (page 33). 

EXAMINATION OF BEECH-LEAVES AT DIFFERENT STAGES OF 
GROWTH. (dr. ZOELLER.) 

Beech leaves und asparagus, their ash-constituents at different periods of growth — 
The amylum of the pahn— Motion of sap in plants — Drain, lysimeter, river, and 
bog water, their constituents— Fontinalis antipyretica from two difl'erent waters, 
ash-constituents — Vegetation of maize in solutions of its food — Experiments on 
the growth of beans in pure and prepared turf, results — Japanese agriculture — 
The cultivated soil of the torrid zone, its exhaustlbility, its manure— Analysis 
of clover by I'incus— Clover sickness, its cause 

THE beech tree (fagiis sylvatica), from which the leaves ex- 
amined were gathered, stands in the Botanical Garden of 
Munich. The leaves marked I, period were taken from the tree 
of four different sizes, on May 16, 1861. The smallest leaves a 
were just unfolded from the leaf-bud, whilst those marked d were 
fully expanded. There were between a and d a difference of four 
days' growth. The other two sets, marked severally h and c, were 
in size and period of growth intermediate between a and d. The 
leaves of the I. period were very delicate, and of yellowish green 
colour. 

The leaves of the II. period were gathered on July 18, those 
of the III. period on October 15, 1861. The leaves of each period 
possessed among themselves tlie same size and firmness of structure. 
The colour of the July leaves Avas dark green, of those of October 
somewhat lighter. 

The leaves of the IV. period were from the same tree, but had 
been gathered in the end of November, 18G0. They had withered 
on the tree, and were quite dry. 



EXAMINATION OF BEECH-LEAVES. 333 

One hundred parts by -weight of the fresh ])eech leaves con- 
tained : — 

I. rcriod. II. III. 

, ' , Period. Period. 

abed 

Dry substance 30-29 22-0-t 21-53 21-52 44-13 43-23 

Water C'J-Tl 7T-yG 78-47 78-46 55-67 50-77 

One thousand fresh leaves contained, iu grammes : — 

Drv substance lO'Ol 15-90 32-63 60-00 116-16 117-53 

AViler 2-2-61 57-26 118-91 218-31 147-04 154-33 

Total weight of 1000 leaves. . 82-62 73-10 151-54 278-31 263-20 271-86 
Ashof dry leaves per cent.. . 4-65 5-40 5-82 5-70 7-57 10-15 

The amount of water in the air-dried leaves of the IV. period 
was 11-89 per cent. The quantity of ash left by the dried leaves 
was 8-70 per cent. 

For the ash analysis of the leaves of the period I., an equal 
number of leaves b, c, d, were incinerated. 

One hundred parts of the ash of the leaves contained: — 



Soda 

Potash 

Magnesia 

Lime 

Sesquioxide of iron. . . 

Phosphoric acid 

Sulphuric acid 

Silicic acid 

Carbonic acid and con- 
stituents not deter- 
mined 

Total 



I. Period. 

ICth May, 

1S61. 



2-30 
29-95 
3-10 
9-83 
0-59 
24-21 
* 

1-19 

28-83 



100-00 



IT. Period. 

ISth July, 

1861. 



2-34 
10-72 
3-52 
26-46 
0-91 
5-18 
« 

13-37 
37-50 



III. Period. 

14th October, 

1861. 



100-00 



1-01 
4-85 
2-79 
34-05 
0-94 
3-48 
* 

20-68 
32-20 



100-00 



lY. Period. 

End of Nov., 

1860. 



24-37 
25-35 



100-00 



* Not determined. 



334 



APPENDIX A. 



Analysis of the ash of the leaves of the horse-chestnut and the ivalnut-tree, 
by E. Staffel. {^An. der Ch'em. iind Fharm.,^ vol. Ixxvi. p. 372.) 





Horse-chestnut. 


Walni 
Spring. 


t tree. 




Spring. 


Autumn. 


Autumn. 


Moisture in 100 parts ) 
of fresh substance, > 
dried at 212° Fahr. . . ) 

Per cents of ash in the 
fresh substance 

Per cents of ash in the 
dried substance 


82-09 

1-376 
7-69 


56-27 

8-288 
7-52 


82-15 

1-092 
7-719 


63-31 

2-570 
7-005 


100 pai-ts of ash con- 
tained— 
Potash 


46-88 
13-17 
5-15 
0-41 
1-63 
2-45 
1-76 
24-40 
4-65 


14-17 

40-48 
7-78 
0-51 
4-69 
1-69 

13-91 
8-22 
8-55 


42-04 
26-86 
4-55 
0-18 
0-42 
2-58 
1-21 
21-12 
1-04 


25-48 


Lime 


53-65 




9-83 




0-06 


Sesquioxide of iron 


0-52 
2-65 


Silicic acid 


2-02 


Phosphoric acid 

Chloride of potassium.. . 


4-04 
1-73 


Total 


100-00 


100-00 


100-00 


99-98 







Analysis of the ash of flowering asparagus shoots, and of withered shoots 
with ripe fruit. — Dr. Zoeller. 





I. 

Flowering 

shoots. 


II. 

Autumn shoots 
with ripe fruit. 


Moisture in 100 parts of the fresh substance, 1 

dried at 212° Fahr J 

Per cents of ash of the fresh substance 


84-34 

0-946 
6-050 


59-23 
4-13 


Per cents of ash of the dried substance 


10-13 






100 parts of ash contain — 
Soda 


5-11 

84-40 

4-69 

9-07 

0-52 

12-54 

1-85 

31-82 


5-25 




11-77 




8-61 




24-05 




0-94 




7-33 




9-68 




87-37 






Total 


100-00 


100-00 







STARCH IN THE STEMS OF PALMS. 335 

The asparagus slioots analysed came from the Botanical Gar- 
den at Munich. Tlie tiowering shoots were cut close to the 
ground, on Juno 20, 1861 ; the autumn shoots Avero cut in the 
same way, from the same plant, on October 28, 1801. 



APPENDIX B (page 41) 

ON THE STARCH IN THE STEMS OF PALMS. 

The quantity of starch in one and the same stem differs to an 
extraordinary degree Avitli the age of the plant, and the periods of 
flowering and fructitication. 

The generation of starch will in some instances rapidly increase 
not only within the cells, but occasionally even at the expense of 
the cellular tissue. Thus, in the root-stock of Sahal Mexicana, an 
abundance of starch is sometimes found, not only in the interior 
of the cells, but also outside the latter. But this phenomena is 
most striking in the East India Sago Palms (Mctroxylon), in which 
it can be clearly observed that the generation of starch proceeds 
in distinct periods, and is in intimate organic connection Avith the 
develoi)ment of the flowers and fruit. The Malays are in the 
habit of speaking of the tree as if it were with young at this pe- 
riod, during which it generates in its interior a large quantity of 
starcli, forming the store of organic matter, out of which are to 
be produced, after rupiefaction, new ligneous particles, and flow- 
ers, and fruit. This statement is peculiarly applicable to the 3Ie- 
troxylon Rumpliii M((rt. (Sagus gemiina liumjih). This tree, 
which is a perfect chemical laboratory for the preparation of 
starch, is monocarpous, that is to say, it flowers and bears fruit 
only once, and then dies. It has by that time attained a height 
of from 28 to 30 feet. The stem, which is cylindrical, and more 
than a foot in diameter, consists of a mere shell, about one and a 
half to two inches thick, of a whitish wood of no great degree 
of hardness. Within the shell is enclosed a mass of spongy tissue 
formed of interlaced fibres, the cells of which are filled with 
starch granules. In the first stage of growth, whilst the stem 
still remains unripe, if the expression may be allowed, it contains 
only an inconsiderable quantity of starch. As growth progresses, 
and the base of the leaf stalks, and the upper part of the stem be- 
gins to be covered witii long fibrous filaments or i)rickles, the 
quantity of starch increases. 

The period of the greatest increase is indicated by the shed- 
ding of these prickles, and by the leaves being covered with a 
sort of white rime, as if powdered lime had been dusted over 
them. The Malays call this stage the Maaptitih, i. e. the tree 



336 APPENDIX B. 

grows white. From the apex of the stem shoots forth at this 
stage the flower-stalk, which at a later period crowns the tree like 
an immense antler, bearing thousands of flowers, which are re- 
placed afterwards by spherical fruit covered with scales. When 
the flower-stalk attains a length of one foot, the tree has entered 
that stage which the Malays term Sacja bonting, that is Avith 
young. A small quantity of the starch is now taken up for the 
formation of the woody fibre of the flower-stalks. Finally arrives 
the period which the Malays term Majang bara, i. e. the young 
comes forth. The flower-stalk at the apex of the stem now at- 
tains a length of four feet, but the spathes out of which the floral 
branches are to project, are not yet opened. The tree may pass 
through these three stages without any great reduction of the store 
of starch ; but at the next stage, termed Batsja Bang, i. e. the 
shoot branches out, when the flower stalk measures from six to 
ten feet in height, and ten feet in circumference, the greater por- 
tion of the starch is formed into thick woody fibre, and still more 
is this the case in the two last stages of the flower (Siriboa) and 
fruit (Bahoa), when there remains no longer any starch. A healthy 
tree produces between 400 and 800 lbs. of starch (the sago pre- 
pared from this is not sent to the European markets, but is con- 
sumed in the country). The palm, which produces the chief por- 
tion of the sago consumed in Europe, is the Metroxylon laeve 
Mart, of Malacca, the wild stems of which give four to five and a 
half picols of sago, whilst two to three picols only are obtained 
from those cultivated in gardens. 



APPENDIX C (page 66). 

VEGETABLE STATICS, LONDON, 1727. 

The experiments made by Hales on the motion of the sap in 
vegetables, may be looked upon as the best model for all times of 
the most perfect method of investigation. That they are still at 
the present day unsurpassed in vegetable physiology may, per- 
haps, be attributed to the circumstance of their dating from the 
age of Newton. They deserve a place in every work treating of 
the physiology of plants. 

In the beginning of his work Hales describes the experiments 
made by him on the motion of the sap in vegetables arising from 
the exhalation from their surface. These experiments were made 
with leafy branches, plants cut ofl:" from the roots, and others still 
retaining their roots. 

The force of the pressure of a column of water, both witli and 
without the cooperation of exhalation, was shown by the follow- 
ing experiment. 



hales' experiments on the motion of the sap. 337 

ITo fixed an apple-branoli, tliroc feet long, half-ineh in diameter, 
full of leaves and lateral shoots, to a tube seven feet long, and five- 
eighths of an ineli in diameter. lie filled the tube with water, 
and then immersed the whole braneli up to the lower end of the 
tube, in a vessel full of water. The water was driven into the 
branch by the pressure of the column of water in the tube, which 
subsided fourteen and a quarter inches in two days. 

On the tliird day he removed the branch and tube out of the 
water, and hung it up in the open air ; the water in tlie tube fell 
now twenty-seven inches in twelve hours. 

To determine the comparative force with which the water is 
driven throuirh the vessels of the ligneous body by pressure alone, 
and by pressure and exhalation combined, Hales joined a leafy ap- 
ple branch to a tul)e nine feet long filled with water. In conse- 
quence of the pressure of the column of water and of the exha- 
lation taking place from the surface of the leaves and twigs, the 
w'ater in the tube (fortieth experiment) s:ink 36 inches in an hour. 
He then cut olf the branch 13 inches below the glass tube, and 
placed the cut portion (with leaves and twigs) upright in a vessel 
Avith water. It was found to imbibe 18 ozs. of water in 30 hours ; 
in which time only G ozs. of water had passed through the 13 
inches of the stem connected with the tube, and that too under 
the pressure of a column of water 7 feet high. 

In three other experiments. Hales shows that though tlie sap- 
vessels of plants will imbibe water plentifully by capillary attrac- 
tion in branches severed from the trunk, as well as in those left in 
connection with the uninjured roots, they have very little power 
to protrude sap out at their extremities, and make it rise in a tube 
fixed to them. 

The motion of the sap, Hales concludes, is to be attributed to 
the exhalation from the surface alone, and he proves that it pro- 
ceeds in an equal degree from the trunk, branches, leaves, flower 
and fruit, and that tiie efiect of the exhalation bears a certain def- 
inite ratio to the temperature and moisture of the air. When the 
atmosphere was charged with humidity little water was imbibed, 
and on rainy days the absor])tion was barely perceptible. Hales 
opens this second chapter of his statics with the following intro- 
troductory remarks : — 

' Having in the first chapter seen many proofs of tlie great 
quantity of liijuid imbibed and perspired by vegetables, I i)ropose 
in this to iiKjuire with what force tliey do imbibe moisture. 

'Though vegetables (■which are inanimate! have not an engine 
which by its alternate dilatations and contractions does in animals 
forcibly drive the blood through tlie arteries and veins, yet has 
nature wonderfully contrived other means, most powerfully to 
raise and keep in motion the sap.' 

In his twenty-first experiment lie laid bare one of the chief 
roots of a thriving pear-tree at a deptli of 2^ feet, cut oft" the end 

15 



838 APPENDIX C. 

of the root, and connected the remaining stump with a glass tube 
filled with water and confined by mercury. This glass tube rep- 
resents the root lengthened. 

By tlie perspiration from the surface of the tree, the root im- 
bibed the water in the tube with such vigor that in six minutes 
the mercury had risen in the tube as high as 8 inches, wliich cor- 
responds to a column of water 9 feet in height. 

This force is very nearly equal to tliat with which the l)lood 
moves in the great crural artery of a horse. ' I found,' says Hales, 
in his thirty-sixth experiment, 'the force of the blood of several 
animals, by tying them down alive upon their backs, then laying 
open the great crural artery where it first enters the thigh, and 
fixing to it, by means of two brass pipes running one into the 
other, a glass tube above ten feet long and one-eighth of an inch 
in diameter. In this tube the blood of one horse rose eight feet 
three inches, and the blood of another liorse eight feet nine inches ; 
the blood of a little dog, six feet and a half.' 

Hales proved by special experiments, that the force of suction 
shown by liim to be possessed by the roots of plants, is exercised 
equally by every individual branch, shoot, leaf, and fruit, in short, 
by every portion of the surface ; that the motion of the sap from 
the root to the branches and leaves continues even when the 
trunk is, in any part, completely stripped of the outer and inner 
bark, and that this force of suction acts not only from the roots 
towards the top, but also from the latter towards the roots. 

He concludes, tVom the results of his experiments, that every 
part of the plant is endowed with a powerful force of attraction. 

We know now that it was not this force of attraction in itself 
that made the mercury and tlie water rise in Hales' tubes ; and 
his experiments clearly show, that the imbibing force of plants, 
and of every leaf and root fibre, arising from surface exhalation, is 
aided by a powerful force from without, which is simply atmo- 
spheric pressure. 

By the evaporation of the water from the surface of plants a vacu- 
um is created therein, and in consequence thereof water and gases 
soluble in that fluid are readily forced in from without and raised 
by the pressure of the atmosphere, and it is this pressure from 
without which, together with capillary attraction, constitutes the 
principal cause of the motion and dilTusion of the sap. 

That the surface of plants possesses the faculty of imbibing 
gases, is most conclusively demonstrated by Hales. In his twenty- 
second experiment he says: — 'The height to which the mercury 
rose in the tube did in some measure show the force with which 
the sap was imbibed, though not nearly the whole force ; for while 
the water was imbibing, the transverse cut of the branch was cover- 
ed with innumerable little hemispheres of air, and many air-bubbles 
issued out of the sap-vessels, which air did in part fill the tube as 
the water was drawn out of it ; so that the height of the mercury 



hales' experiments. 339 

could only be proportionable to tbo excess of the quantity of water 
drawn off, above the quantity of air whicli issued out of tlie wood. 

'And if the quantity of air, wliich issued from the wood into 
the tube, had been equal to the quantity of water imbibed, then 
the mercury would not have risen at all, because there would 
have been no room for it in the tube. 

' But if nine parts in twelve of the water be imbibed by the 
branch, and in tlie meantime but three such j'arts of air issue into 
the tube, then the mercury must needs rise near six inches, and so 
proportionately in different cases.' 

When, in Hales' experiments, the root, the stem, or a branch 
had been wounded in any part by cutting off root fibres, or buds, 
or smaller twigs, the imbibing power was found to be diminished 
in the other parts (because at those wounded spots the difference 
in the pressure was more readily equalized by air finding its way 
.in). The imbibing power was greatest about fresh cuts, but it 
gradually diminished until, after a few days, it remained no stronger 
about the cut than about the uninjured parts. Hales further con- 
cludes the exhalation from the surface to be the powerful cause 
that conveys nutriment to the plant from tlie parts surrounding it. 
If the i)roper proportion between the exhalation and the supply 
of food is in any way disturbed, the plant sickens and dies. If, in 
hot summers, the soil is unable to supply to the roots the moisture 
carried off in the course of the day by exhalation from the leaves, 
&c., and the tree or a branch of it is dried up, the motion of the 
sap ceases in such parts. Once dried up, the original action can- 
not be restored by capillary attraction alone. Exhalation is the 
chief condition of the life of the plant, serving as it does, to effect 
and maintain a continual motion of the sap, and a constantly re- 
curring change in its condition. 

' By comparing,' says Hales, ' the surface of the roots of a 
plant with the surface of the sajne plant above ground, we see the 
necessity of cutting off many brandies from a transplanted tree. 
Suppose, upon digging the i)lant up, in order to transplant it, half 
the roots be cut off (which is the case of most young transplanted 
trees), then it is plain that but half the usual nourishment can be 
carried up through the roots, and that accordingly the perspiring 
surface above ground must be correspondingly reduced in order to 
restore the proper proportion between it and the imbibing surface 
under ground.' In the following observations on hop vines, Kales 
shows tlie effect of suppressed persj)iration : — 

' The soil of an acre of ground on which 9,000 hop-vines are 
growing, must supply to the plants, through the roots, in July, 
3G,000 ozs. of water in twelve hours. This is the (piantity of 
water which during this time is exhaled by them, and which they 
must have to be in a thriving condition. 

'In a kindly state of the air, this moisture is daily carried off 
in s'utBcient quantity to keep the hops in a healthy state ; but in a 



310 APPENDIX C. 

rainy moist state of air, without a due mixture of dry weather, too 
ranch moisture hovers about the hops, so as to hinder, in a great 
measure, the kindly perspiration of the leaves, whereby the stag- 
nating sap corrujtts and breeds mould. 

' This was the case in the year 1723, when ten or fourteen days 
almost continual rains fell, about the latter half of July, after four 
months' dry weather ; upon which tlie most flourishing and prom- 
ising hops were all infested with mould in their leaves and fruit, 
while the then poor and unpromising hops escaped and produced 
plenty ; because they being small, did not perspire so great a 
quantity as the others ; nor did they confine the perspired vapor 
so much as the large thriving vines did in their shady thickets. 

' This rain on the then warm earth made the grass shoot out as 
fast as if it were in a hotbed ; and the apples grew so precipitately, 
that they were of a very fleshy constitution, so as to rot more re- 
markably than had ever been remembered. 

' The planters observe, that when mould has once seized any 
part of the ground, it soon runs over the whole, and that the grass 
and other herbs under the hops are infected with it; probably 
because the small seeds of this quick growing mould, which soon 
come to maturity, are blown over the whole ground; which 
spreading of the seed may be the reason why some grounds are 
infected with fen for several years successively. 

' I have,' says Hales, 'in July (the season for fire-blasts, as the 
planters call them), seen the vines in the middle of a hop ground 
all scorched up, almost from one end of a large ground to the 
other, when a hot gleam of sunshine has come immediately after 
a shower of rain ; at which time the vapors are often seen with 
the naked eye, but especially with reflecting telescopes, to ascend 
so plentifully as to make a clear and distinct object become imme- 
diately very dim and tremulous. Nor was there any dry gravelly 
bed in tlie ground, along the course of this scorch. It was, there- 
fore, probably owing to the much greater quantity of scorching 
vapors in the middle than outside of the ground, and that being a 
denser medium, it was much hotter than a more rare medium. 

' The gardeners about London have, to their cost, too often had 
occasion to observe a similar eftect, when they have incautiously 
put bell-glasses over their cauliflowers early on a frosty morning, 
before the dew was evaporated oft' them ; which dew being raised 
by the sun's warmth, and confined within the glass, did then form 
a dense transparent scalding vapor, which burnt and killed the 
plants.' 

These observations translated into the language of the present 
day clearly show how acutely and exactly Hales comprehended 
the influence of perspiration upon the life of plants. 

According to him, the proper thriving of plants depends upon 
the supply of food and moisture from the soil, which again is gov- 
erned in a measure by a certain temperature and dryness of the 



DRAINAGE WATER. 



341 



atmosphere. Tlie imbibing power of plants, — the motion of the 
sap in them, is dependent npon exhalation ; the quantity of food 
imbibed and needed for the functions of the plant, is proportionate 
to the quantity of moisture exhaled in a given time. If the plant 
has imbibed a maximum of tluid, and the exhalation is hindered by 
a low temi)erature, or by long continued wet weather, tlie supply 
of food or the nutrition of the plant stops, the sap stagnates, and 
an alteration ensues tending to the generation of parasitical mi- 
croscopic growths. If rain falls after hot weather, followed by a 
strong heat without wind, and every part of the plant is surround- 
ed with an atmosphere saturated with moisture, cooling by further 
exhalation ceases, and the plants succumb to the sun-blasts. 



APPENDIX D (page 98). 

ANALYSES OF DRAINAGE, LYSIAIETER, RIVER AND MARSH 
WATER. 

I. — Drainage Water. 

Thomas Way found in drainage water taken from seven differ- 
ent fields, the following constituents (' Journal of the Roy. Agric. 
See.,' vol. xvii. 133) :— 



Potash 

Soda 

Lime 

Magnesia 

Sesquioxide of iron and 

alumina 

Silicic acid 

Chlorine 

Sulphuric acid 

Phosphoric acid 

Ammonia 



Grains in 1 gallon = 10,000 grains of water. 



trace 
1-00 

4-85 
0*68 

0-40 

0-95 
0-70 
l-t)5 
trace 

0-018 



trace 
2-17 
7-19 
2-32 

0-05 

0-45 
1-10 
5-15 
0-12 
0-018 



0-02 
2-26 
6-05 
2-43 

0-10 

0-5.5 
1-27 
4-40 
trace 
0-018 



0-05 
0-87 
2-26 
0-41 



1-20 
0-81 
1-71 
trace 

0-012 



trace 
1-42 
2-52 
0-21 

1-30 

1-80 
1-26 
1-29 
0-08 
0-018 



0-22 
1-40 
5-82 
0-93 

0-35 

0-G5 
1-21 
3-12 
0-06 
0-018 



trace 
3-20 

13-00 
2-50 

0-50 

0-85 
2-62 

y-oi 

0-12 
0-OOG 



Very similar results were obtained by Dr. Iv rocker in his analy- 
ses of drainage water from Proskau. (See Liebig and Kopp's 
' Jahresbericht ' for 1853, page 742.) 



342 



APPENDIX D. 





Drainage 


Water 


(in 10,000 parts) 






a 


b 


c 


d 


e 


/* 




0-25 
0-84 
2-08 
0.02 
0-70 
0-04 
0-02 
0-11 
0-OS 
0-07 


0-24 

0-84 
2-10 
0-02 
0-fi9 
0-04 
0-02 
0-15 
0-08 
0-07 


0-16 
1-27 
1-14 
0-01 
0-47 
0-04 
0-02 
0-13 
0-07 
0-06 


0-06 
0-79 
0-17 
0-02 
0-27 
0-02 
0-02 
0-10 
0-03 
0-05 


0-63 
0-71 
0-77 
0-02 
0-27 
0-02 
0-04 
0-05 
0-01 
0-06 


0*56 




0-84 


Sulphate of lime 


0-72 




0-02 


Carbonate of magnesia 


0-16 


Carbonate of protoxide of iron. . . 
Potash 


0-01 
0-06 


Soda 


0-04 


Chloride of sodium 


0-01 


Silica 


0-05 






Total solid matter 


4-21 


4-25 


3-37 


1-53 


2-58 


2-47 







II. — Lysimeter Water. 

Lysiraeter water is atmospheric water passed by means of suit- 
able apparatus (Lysimeter) througli difierent soils, and collected 
after passing through. (See pp. 99, 100.) 

The chemical analyses embraced four series, and were made by 
Dr. Zoeller. 

1. — Series of analyses made in 1857. 

The experiments were made with five different soils, 1 square 
foot of each earth, 6 inches deep, being placed in the several 
lysimeters. The quantities given represent the amount of 
atmospheric water that passed through the several lysimeters 
from April 7 to October 7, 1857. I. Manured calcareous soil, 
with vegetation (barley). II. Unmanured clay soil, with vege- 
tation. III. Unmanured clay soil, without vegetation. IV. 
Manured clay soil, without vegetation. V. Manured clay soil, 
with vegetation. (2 lbs. cattle-dung, without straw, were sev- 
erally used to manure the earth in lysimeters I., IV., and V. 



* a. Drainage water from land A (a clay soil resting on a subsoil of cal- 
careous loam or clay), collected 1st April, 1853. — h. The same, collected 1st 
May, 1853, after a heavy fall of rain (218 cubic inches on the square foot). — 
c. Drainage water from the same soil, mixed with drainage water from a 
humous clay soil, with calcareous clay or loam as subsoil, collected in Octo- 
ber, 1853. — d. Drainage water from land B (tile-drained: subsoil of calcare- 
ous clay or loam), collected in October, 1853. — e. AVatcr passing through the 
water-furrows from a heavy clay soil, collected in the beginning of June. — 
/. The same, collected in the middle of August, after heavy rains. 



LYSIMETER WATEK. 



3-i3 



Quantity of water passed 1 
through soil iu lysiuieter. ) 



Solid residue left at 212° F. 
Ash of solid residue 



cub. cent. cub. cent. cub. cent. cub. cent. 
9845 18575 18148 19790 



Potash 

Soda 

Lime 

Magnesia ,. .. . 

Sesquioxide of iron. 

Chlorine 

Phosphoric acid 

Sulphuric acid 

Silicic acid 

Clay and saud 



ir. 



III. 



IV. 



grammes. 
4-651 
3-127 



Total. 



Deduct equivalent of oxygen | 
corresponding to chlorine ) 



Balance 

Carbonic acid and loss. 



Total 4-651 



0-064 
0-070 
1-436 
0-203 
0-013 
0-566 
0-022 
0-172 
0-103 
0-089 



2-738 
0-127 



2-611 
2-040 



grammes, grammes. 
4-73 5-291 

3-283 3-545 



C-044 
0-104 
1-070 
0-165 
0-119 
0-177 
trace 
0-504 
0-210 
0-074 



0-037 
0-1.35 
1-285 
0-024 
0-150 
0-379 
trace 
0-515 
0-.317 
0-112 



2-467 
0-040 



2-427 
2-303 



2-954 
0-085 



2-869 
2-422 



4-730 1 5-291 



grammes. 
6-04 
4-245 



0-108 
0-470 
1-354 
0-058 
0-114 
0-781 
trace 
0-580 
0-188 
0-045 



eub. cent. 
12302 



grammes. 

3-GSO 
2-610 



3-698 
0-176 



3-522 
2-518 



6-040 



0-047 
0074 
1-136 
0-063 
0-053 
0-434 
trace 
0-412 
0-115 
0-047 



2-381 
0-095 



2-286 
1-400 



-686 



1,000,000 litres of water, passed through six inches of the soils 
already described, contain — 





I. 


II. 


III. 


IV. 


V. 


Solid residue left at 212° F.. . . 
Ash contained in it 


grammes. 
472-32 
317-62 


grammes. 
254-64 
176-74 


grammes. 
292-64 
194-78 ■ 


grammes. 

'305-20 

214-50 


grammes, 
291-50 
212-16 






Potash 


6-50 

7-11 

145-86 

20-52 

1-32 
57-49 

2-23 
17-47 
10-46 


2-37 
5-60 
57-60 
8-88 
6-35 
9-52 

27-13 
11-35 


2-03 
7-43 

70-80 
1-32 
8-26 

20-87 

27-82 
17-46 


5-46 

23-74 

68-41 

2-93 

5-76 

39-46 

20-30 
9-50 


3-82 


Soda 


6-02 


Lime 


92-34 




5-12 




4-30 




35-27 






Sulphuric acid 


33-49 


Silicic acid (soluble) 


9-34 







2. — Series of analyses made in 1858. 

The -waters analysed were obtained from six soils, and repre- 
sent the quantity of atmospheric water that passed, from May 10 
to Nov. 1, 1858, through a layer of earth of a s<iuare foot of 
surface and 12 inches deep. The earth was ordinary unmanured 
alluvial lime soil from the Isar. The plant selected for cultiva- 
tion was the potato. I. Unmanured, and without vegetation. 



su 



APPENDIX D. 



II. Unmanured, with vegetation. III. Manured, 10 grammes 
common salt, with vegetation. IV. Manured, 10 grammes 
nitrate of soda, with vegetation. V. 10 grammes guano, with 
vegetation. VI. Manured, 20 grammes phosphorite made soluble 
with hydrochloric (?) acid, with vegetation. 



Quantity of water passed ) 
through the soil J 



Solid residue left at 212° F. 
Ash of the solid residue. . . 

Soda 

Potash 

Magnesia 

Lime 

Oxide of iron 

Chlorine 

Phosphoric acid 

Nitric acid 

Sulphuric acid 

Silicic acid 

Sand 

Sum 

Less the amount of oxy- 
gen equivalent to the 
chlorine 

Sum 

Loss and carbonic acid.. . . 

Sum 



cu. cent. 
29185 



8-985 
6-591 



0-250 
0-075 
0-432 
2-416 
0-115 
0-227 
trace 

0-132 
0-266 
0-155 



4-068 
0-051 



4-017 
4-968 



8-985 



cu. cent. 
25007 



srms. 
8-214 
6-094 



0-245 
0-066 
0-443 
2-467 
0'033 
0-237 
trace 

0-147 
0-301 
0-237 



4-226 
0-053 



4-163 
4-051 



8-214 



grms. 
14-198 
12-292 



3-290 
0-034 
0-454 
2-356 
0-104 
3-925 
0-009 

0-118 
0-384 
0-155 



10-829 

0-884 



9-945 
4-253 



14-198 



IV. 



V. 



cu. cent.Icu. cent. 
17466 16520 



grms. 
7-681 
5-553 



1-2.55 
0-035 
0-264 
1-792 
0-083 
0-177 
trace 
3-267 
0-1S2 
0-303 
0-105 



7-463 
0-039 



7-424 
0-257 



7-671 



grms. 
4-864 
3-704 



0-301 
0-032 
0-382 
1-378 
0-096 
0-317 
0-007 

0-197 
0-226 
0-062 



2-998 
0-071 



2-927 
1-937 



4-864 



cu. cent. 

30850 



grms. 
8-001 
6-192 



0-233 
0-029 
0-374 
2-645 
0-117 
0-238 
0-015 

0-666 

0-224 
0-083 



4-644 
0-053 



4-591 
3-410 



8-001 



1,000,000 litres of water, passed through 10 inches of the soils 
already described, contain — 





I. 


II. 


III. 


IV. 


V. 

grms. 

294-42 
224-21 


VI. 


Solid residue left at 212° F. 
Ash contained in it 


grms. 

307.86 
225-83 


grms. 
328-46 
243-69 


grms. 

504-58 
436-84 


grms. 

439-76 
374-04 


gi-ms. 

259-35 
200-71 


Soda 


8-56 
2-56 
14-80 
82-78 
3-94 
7-77 

4-52 
9-11 


9-79 
2-63 
17-71 
98-05 
3-31 
9-47 

5-87 
12-03 


116-92 

1-20 

16-13 

83-73 

3-69 

139-49 

0-31 

4-19 
13-64 


71-85 
2-00 

15-11 

102-59 

4-75 

10-13 

187-04 
10-42 
17-34 


18-22 
1-93 

23-18 

83-41 
5-81 

19-18 
0-42 

11-09 
13-68 


7-55 


Potash 


0-94 




12-12 




85-73 




3-79 




7-71 


Phosphoric acid 


0-48 




21-59 


Silicic acid 


7-26 



LYSIMETER WATER. 



345 



3. — Series of analyses made in 1859. 

The waters analysed -were obtained from six soils, and repre- 
sent the quantity of atmospheric water that passed from March 
20 to Nov. IG, 1859, through a layer of earth of a square foot of 
surface and 12 inches deci>. The earth was ordinary unnianurcd 
alluvial lime soil from tlie Isar (garden soil). All the soils were 
in grass. I. Unmanured. II. Manured, 17-8 grammes nitrate of 
potash. III. Manured, 15-4 grammes sulphate of potash. IV. 
Manured, 17'8 grammes nitrate of potash, and 3-66 grammes 
phosphoride made soluble with 2 grammes sulphuric acid. V. 
Manured, 15-4 grammes sulphate of potash, and 3-66 grammes 
of phosphorite made soluble as above. VI. Manured, 12-3 
grammes carbonate of potash. 





I. 


IL 


in. 


IV. V. 


VI. 


Quantity of water passed 1 
through the soil ) 

Solid residue left at 212' F. 
Ash of the solid residue. . . 


cu. cent. 
20201 

grms. 

4-5631 

3-192 


cu. cent. 
14487 

grms. 

11-4272 

8-861 


cu. cent. 
20343 

grms. 
15-1967 
13-644 


cu. cent. 
17491 

grms. 
13-6805 
10-681 


cu. cent. 
23205 

grms. 

20-784 
17-663 


cu. cent. 
22483 

grms. 

6-5873 

4-614 


Soda 


0-044 
0-024 
0-253 
1-530 
0-072 
0-035 
trace 
0-289 
1-125 
0-178 
0-044 


0-069 
0-166 
0-302 
3-483 
0-057 
0-080 
trace 
0-205 
5-913 
0-271 
0-021 


0-083 
0-205 
0-296 
5-360 
0-072 
0-202 
trace 
6-527 
1-301 
0-208 
0-036 


0-030 
0-231 
0-285 
4-83S 
0-084 
0-132 
trace 
2-104 
5-248 
0-230 
0-025 


0-085 
0-244 
0-320 
7-112 
0-088 
0-283 
trace 
9-124 
1-401 
0-280 
0-056 


0-038 


Potash 


0-112 




0-117 




1-963 


Oxide of iron 


0-053 


Chlorine 


0-127 


Phosphoric acid 


trace 




1-524 


Nitric acid 


1-390 


Silicic acid 


0-269 


Sand 


0-097 






Sum 


3-594 

0-007 


10-567 

0-018 


14-290 
0-045 


13-207 
0-029 


18-993 
0-063 


4-690 


Less the amount of oxy- 1 
gen equivalent to the > 
chlorine ) 


0-023 




8-5g7 
0-9761 


10-549 
0-8782 


14-245 
0-9517 


13-178 
0-5025 


18-930 
1-854 


4-Gfi2 


Loss and carbonic acid 


0-9258 


Sum 


4-5631 


11-4372 


15-1967 


13-6805 


20-784 


5-5878 











1,000,000 litres of water, passed through one foot of the soils 
already described, contain — 



lo» 



346 



APPENDIX D. 





I. 

grins. 
225-38 
158-0 


II. 


III. 


IV. 


V. 


VI. 


Solid residue left at 212' F. 
Ash contained in it 


grms. 
788-78 
611-64 


grms. 

746-84 
670-52 


grms. 

782-14 
610-65 


grms. 

895-66 
761-36 


grms. 

248-48 
205-17 


Soda 


2-17 

1-18 

12-52 

75-73 

3-56 

1-73 

14-30 

55-69 

8-81 


4-76 

11-45 

20-84 

240-42 

3-93 

5-52 

14-15 

408-15 

18-70 


4-07 

10-07 

14-54 

263-41 

3-53 

9-92 

320-76 

63-93 

10-32 


1-71 

13-20 

16-29 

276-59 

4-80 

7-54 

120-29 

300-04 

13-14 


3-66 

10-51 

13-79 

306-48 

3-79 

12-19 

393-19 

60-37 

12-06 


1-68 


Potash 

Magnesia 


4-98 
5-20 


Lime 


87-29 


Oxide of iron 


2-35 


Chlorine 


5-64 




23-30 


Nitric acid 


61-76 


Silicic acid 


11-96 







4. — Series of analyses made in 1859, 1860. 

This series is a direct continuation of the tliird. Tiie waters 
analysed passed through the same soils through which the waters 
of the third series had already passed. The fourth series of ex- 
periments continued from Nov. 16, 1859, to April 12, 1860. 





I. 


II. 


III. 


IV. 


V. 


VI. 


Quantity of water passed ) 
through the soil ) 

Solid residue left at 212° F. 
Ash of the solid residue. . . 


cu. cent. 

13500 

grms. 

2-424 
2-071 


cu. cent. 

12332 

grms. 

2-205 
1-682 


cu. cent. 

13760 

grms. 
2-860 
2-395 


cu. cent. 

13150 

gi-ms. 

2-640 
2-086 


cu. cent. 

15232 

grms. 

3-172 
2-599 


cu. cent. 

14850 

grms. 

2-691 
2-220 


Soda 


0-021 
trace 
0-065 
0-770 
0-061 
0-140 
trace 
0-025 
0-119 
0-170 


0-024 
0-OOS 
0-058 
0-859 
0-066 
0-042 
trace 
0-101 
0-099 
0-144 


0-028 
0-012 
0-069 
1-016 
0-097 
0-093 
trace 
0-043 
0-487 
0-118 


0-022 
0-009 
0-074 
0-938 
0-075 
0-068 
trace 
0-077 
0-474 
0-153 


0-028 
0-015 
0-070 
0-952 
0-135 
0-091 
trace 
0-029 
0-527 
0-123 


0-019 


Potash 

Magnesia 


0-015 

0-063 




1-057 




0-049 




0-084 


Phosphoric acid 


trace 


Nitric acid 


0-046 




0-185 


Silica and sand* 


0-136 








1-371 
0-024 


1-401 
0-009 


1-963 
0-020 


1-890 
0-015 


1-970 

0-020 


1-654 


Deduct the amount of) 
oxygen equivalent to >• 
the chlorine ■ ) 


0-018 




1-347 
1-077 


1-392 
0-813 


1-943 
0-917 


1-875 
0-765 


1-950 
1-222 


1-636 


Loss and carbonic acid.. . . 


0-955 


Sum 


2-424 


2-205 


2-860 


2-640 


3-172 


2-691 







* The quantity of sand very small. 



LYSIMETER WATEE. 



347 



1,000,000 litres of water, passed through 10 inches of the soils 
already described. 





I. 


II. 


III. 


IV. 


V. 


VI. 


Solidrcsidueleft at 212^F. 
Ash contained in it 


grms. 
179-:)i3 
153-47 


grms. 

178-80 
136-39 


grms. 

207-71 
174-07 


grms. 

200-81 
158-69 


grms. 
208-24 
170-62 


grms. 

lSl-21 
149-49 




1-5G 

4-86 
57-04 

4-52 
10-43 

1-91 

8-86 

12-60 


1-94 
0-64 
4-70 
GO -49 
5-35 
3-40 
8-19 
8-02 

11-67 


2-04 
0-92 
5-02 

73-87 
7-06 
6-76 
3-17 

35-45 

8-60 


1-73 
0-69 
5-56 

71-39 
5-73 
5-21 
5-91 

36-08 

11-65 


1-83 
0-98 
4-59 

62-50 
8-86 
5-97 
1-90 

34-59 

8-01 


1-27 




1-01 




4-24 




71-17 


Oxide of iron 


3-29 


Chlorine 


5-65 
3-09 




12-45 


Silicic acid with a little | 
sand , j 


9-15 



Compare 'Annal der Chem. iind Phar.,' bd. 107, s. 27"; 
'Ergebiiisse landwirthsch. itiul Versuche der Versuchstation, 
Miinchen,' II. Heft, s. 65, uiid III. Heft, s. 82. 

Analysis of ashes of plants from the 7'ivers Ohe and her. — Dr. Wittsteix. 



Chloride of sodium . 

Potash 

Soda 

Lime 

Magnesia 

Alumina 

Oxide of iron 

Oxide of manganese. 

Sulphuric acid 

Phosphoric acid 

Silicic acid 

Carbonic acid 

Sum 



Fontinalis 


A 


Qtipyretica* 


from the Ohe. 


IV 


jm the Iser. 


0-346 




0-834 


0-460 
1-745 


I 

\ 


2-325 


2-755 




18-150 


1-133 




5-49S 


9-272 




1-616 


17-039 




9-910 


4-555 




0-850 


1-64S 




2-827 


trace 




5-962 


OIOUO 




51-494 


99-953 




99-406 



* The great difference in the composition of the ashes of one and the same 
plant arises, according to Dr. Nageli, less perhaps from the diflbrent amount 
of these matters in the water than from ditference of age in the plauis, and 
probably more still from other plants which nestle in the moss. 



348 



APPENDIX D. 



^ 

^ 








f O 


r -s^ .• 

































0?;^ ci 


■* CO 03 CO 


§1 


(M 




0) 


CO 


CJi 









<» 




T' ■'r 


. 10 xh 




i^ 


^ 


I 





"P 





p 


1 




,a 


s-sl 


(>1 00 ^ T^ 


1 


^ 


iH 


1 




CO 


IW 


b 


i 




§ 


















CO 









o 


CL, 
























r-l 




^ 2 


10 ^ CO c 




0: 


C-: 






1.0 


""^ 


<T> 


CO 






c§3 
^° 1 




■to C] 















CM 


5 


C^ 


10 




a 

2 


00.- 





1 








I 


u 





^ 




(M 




000 
000 


6 


1 



b 



b 


1 


1 




b 


p 
b 




b 




b 


•a 

o 


fcH 


'- Ti' 






























■ c3=s 


01 To 1-1 t^ .-H 


£0 


J- 










Si 




p 




J2 


1=3 a 




i-' 


. -* T- 


01 






1 


u 


10 


^ 


1 


a 


ffl 


i> i- <i> Qi CO 

T-l 


CO 


cj) 


1 


c3 


b 


b 


b 



1 


O ^ 
>-5 


a 






























oi 




^ 








~ 










cT 








"sa 

2 


C5 CO CO (M a- 


CJ 


i~ 




1(0 





KO 


10 


[« 


o 


10 ■* OT (N 


ir 







S) 




KO 





KO 




f? 


00000 





c 


1 








■* 


OT 


-^ 


w 


0000c 





c 


1 







P 


p 


p 




0000c 


C 


c 




b 


b 


b 


b 


c 


' °2y 




„ 








~ 










~~^ 











t-- CO ■* 0- 




CO 


0) 




c 












to 


o"© :^ 


rH OJ CS r- 


■?" T' "^ 


T 


c^ 


p 


1 






>-<2 S 


c'o !■- 


r-< 00 CO 


dq 1^ 03 


1 


oc 




b 








„^ o a 






i-H I-H 










-* 







n 
































,1(0 00 ■» -* CC 


S: 


en C 




CN 


Kt 


CO 


00 




a 

o 


cSa 

i-HO g 







a 












T-l C 


000 


t, 


<s 


CO 


(» 


^ 




p 9 


00c 


cj 


c 










£ 


OOOOOOOC 


t 


b b 


b 


b 






*• to 






























' . 


c2 c 


CO 


(M 


-* 


J^ Ol 


CO 


CO in 


c- 


T-H 















(M 


CO 


C 


CO 


CO 


<^. 


CO 




(N 


CO 









i 


HH 


§"0 *J 


i:- 


C/5 l_C 


^- 


en 




CO 









uo 


p 


1 




^'i^ 2 


6 




(M 


4* 


CD 


b 


OJ 


b 


I-H 




t- 


b 


I 






.=53 








CO 












5 











.a . 
























'"' 






































a 


to 


CO 


CO 


c- 





^ 





cr 


CO 


<» 


uo 


<> 


(M 







eta 


CC 






CO 


1- 


CO 


cx 


tN 


CO 






■* 


CX) 




p 




5 




0: 


ira 


c 


i^ 







c~ 


1(0 


ICO 


55 


£ 


-1 

61) 


C 





C 






c 


CN 





c 


H 




(M 


CO 


c 





C 


C 














c 


c 


c 


CM 




1 




6 


b 6 


C 


b 




b 


b 


b 


b c 


b 


b 




c ^ C 


i^ 10 CC 


CO 1^ 1(0 CO I- 







^ 






CO <:C 




CO CO CO CO c 







^ 


S"© ij 


CO CJ Ol c- 


b rH !M r- 


CO c<) «: 





1 




o 


y-S. g 


r-1 00 C^ t^ 


I- 


CO i- K 


b 


1 




1 ■ 


«oa 






















i> 





































a 


«3 a 


iraoocMcoiraj^jt-oiiOi-ic 


i(j 


KO 




o- 


OSCOCOCOrHCOCOCMCOC 


CM 


<M 




g 


— it-HCl^rHOOT- 


10 r— I IT 


CO 






^ 


OOr-lOOOOOOi- 




KO 


-* 




pOpOOppppp.;- 











1 


boooooooboc 


b 


b 






























0} 


bi 






























3 


a 






























r2 

































































'm 
































(U 


'S 






























^ 


C3 










£ 




















r2 











£ 






















"o 
w 


a 










c 




















cw 


Cw 








fC 
















;r 


















c 


C 










c 


tJ 


'c 







>> 


^ 










f 


Ic 








•r- 


cd 




























c 





















k 


c 


) 




c 




C3 




"E 


1 


£ 


1 


C3 








a 


a 


1 t 






c3 


c 


J3 





_t 


3 


B 

a" 






- 




■fc 


a 
1 


C 


'1 


a 









"i 


J, 
-2 


"rt 








1= 


!2 


3 "c 




'x 


"a 


-a 




t. 














<- 


> t 


J p. 


1- 


^ 


C 


02 


Ph 


a 





H 


EH 



MOSS WATER. 



349 



IV. — Moss Watn' from the neighhourlwod of SchleissTiem. — Dr. 

"WiTTSTEIX. 



The composition of tlie water was found to be as follows :- 



Chloride of sodium 

Potash 

Soda 

Lime 

Magnesia 

Alumina 

Oxide of iron 

Sulphuric acid 

Phosphoric acid 

Silicic acid 

Carbonic acid 

Organic matter 

Total amount of solid matter 

Total amount of inorganic matter 



In 1000 grammes 
of water. 



0-00280 
0-00022 
0-00551 
005266 
0-00921 
0-00029 
0-00197 
0-00372 
0-00002 
0-00069 
0-03943 
0-13771 



0-25423 
0-11652 



In 100 parts of 
solid matter. 



1-101 

0-086 

2-167 

20-723 

3-627 

0-114 

0-775 

1-466 

0-008 

0-271 

15-595 

54-067 



100-000 



APPENDIX E (page 113). 



VEGETATION OF LAND PLANTS IN THE WATERY SOLUTIONS 
OF THEIR FOOD. 



In experiments on the vep;etation of land plants in the watery- 
solutions of tlieir food, great attention must be paid to the tenden- 
cy of the fluid to become alkaline by the process of vegetation, as 
land plants always die in alkaline solutions. Great care must 
therefore be taken to keep the fluid neutral (very faintly alkaline) 
or feebly acid. Knop attained this object by frequently transfer- 
ring his plants to fresh solutions ; Stohmann, by placing the plants 
from the commencement in feebly acid solutions, and at a later 
period transferring them sometimes to fresh solutions, and at 
other times removing the alkaline reaction by frequent addition 
of a small quantity of acid. 

The tendency of solutions to become alkaline by means of the 
plants vegetating in them, and the injurious effect of an alkaline 
solution on the growth of plants, were observed by Knop and 
Stohmann. 

' In the following are communicated the experiments of Knop 
and Stohmann on the vegetation of maize, in watery solutions. 



350 



APPENDIX E. 



I. — Ex2Jeriments of Knop. 

Knop based his experiments with maize on the earlier observa- 
tions which he had made on the vegetation of barley and cresses 
(see'Chem. Central Blatt,' 1861, s. 564). According to these 
observations the graminero require for their growth nothing more 
than a normal solution, which contains sulphate of magnesia, 
nitrate of lime, and nitrate of potash, according to the proportion 
MgOSOs + 2CaON05 + 2KO]SrO.., in which phosphate of iron was 
suspended, and phosphate of potash as required was dissolved. 
The normal solution A made according to the above formula con- 
tained in grammes — 

100 cent. cub. 500 cent. cub. COO cent. cub. 

Nitric acid 0-2160 1-0800 1-2960 

Sulphuric acid 0-0495 0-24T5 0-2970 

Lime 0-06S4 0-3420 0-4104 

Magnesia ' 0-0233 0-1165 0-1398 

Potash 0-0940 0-4700 0-5640 



0-4512 



2-2560 



2-7072 



In consequence of using the solution in a more dilute form in 
the first period, in order to promote a better radication, 600 cubic 
centimetres of the above solution were employed at this time ; at 
every other period, 500 cubic centimetres were measured off, and 
to this last quantity the phosphate of potash was now added in 
the proportion indicated. The mixture, therefore, had the fol- 
lowing composition in the five periods. The potash which was 
added as KOPOo, and as KONOi, are given separately and united 
with a bracket. 

Period 

I. 12 cent. cub. solution of KOPO5,* 600 cent. cub. normal solution A. 

II. 10 " " 500 " " 
III. & IV. 20 " " 500 

V. 30 " " 500 " " 

In these solutions are contained in grammes, — 





Per. I 


Per. II. 


Per. Ill &IV. 


Per. V. 


Nitric acid 


1-2960 
0-2970 
0-0750 
0-4104 
0-1398 
0-5640 
0-0490 


' 1-OSOO 
0-2475 
0-0625 
0-3420 
0-1105 
0-4700 
0-0408 


1-OSOO 
0-2475 
0-1250 
0-3420 
0-1165 
0-4700 
0-0816 


1-0800 


Sulphuric acid 

Phosphoric acid 

Lime 


0-2475 
0-1875 
0-3420 


Magnesia 


0-1165 


Potash 1 


0-4700 
0-1224 




2-8312 


2-3593 


2--1626 


2-5659 



* 10 cent. cub. of the solution contained exactly 1 decigramme of KOPO5 



EXPERIMENTS ON VEGETATION IN SOLUTIONS. 351 

With tlio exception of tlio mixture used in Period V., tliere 
was added to the others also O'l gramme of i)liosphatc of iron. 

The duration of these periods was accidental, depending on 
fluctuating meteorological conditions of the atmosi)here, but was 
so far regulated that a distant i)eriod was marked whenever 
almost exactly 1 litre of water had been exhaled througli tlio 
leaves of the plants. At this time the remainder of the liquid 
was drawn off for analysis, and the vessel filled with a fresh solu- 
tion. 

In the following the results of the analysis are given along 
with the chief periods and cii'cumstances of the experiments. In 
the analytical results in column a, is placed the total quantity of 
each acid, and salt received by the plant in that particular period ; 
in column b, the bases and acids found by analysis in the remain- 
der of the tluid ; in column o, the difference between a and b, 
indicating the quantity of bases and acids absorbed by the plants. 
Further, the relations of the bases to each other, and that of mag- 
nesia to sulphuric acid (calculated from column a), are given ; the 
quotients also express the proportions in which these matters 
were given to the plants at the beginning of the lieriod. Imme- 
diately underneath, indicated by '' absorbed," are placed the same 
proportions, calculated from column o, in order to show in what 
ratio the plant has selected these matters (when there does exist 
a determinate power of selection). 



SUMMARY OF TUE FOOD GIVEN TO A PLANT OF MAIZE 
AND ASSIMILATED BY IT 

I. Period. From Hay 12 to June 12. — At the commencement 
the plant weighed 8 grammes * ; and had six leaves with a surface 
of 264 square centimetre.^ ; water exhaled during the time ~ 1 
litre. This period was divided into three sections, in which at 
first dilute solutions were used. The mixtures were in, — 

Section I. 
Solution of KOPOs . . 2 cent. cub. 

Normal solution A 100 " 

Distilled water 198 " 

Total fluid 300 " 300 " 306 " 

Phosphate of iron 01 gramme. O'l gramme. 0"1 gramme 

There were added as the solution was absorbed by the plant, — 



Section II. 


Section III. 


4 cent. cub. 

200 
90 


6 cent. cub. 

300 



* The maize seed were made to germinate in the month of April in well 
washed sand; the young plants weighed on the 12th May, 8 grammes; on 
drying the residue weighed scarcely more than the seeds. 



352 APPENDIX E. 

I. Section = 80 cent. cub. distilled water 
II. " = 350 " " 

III. " = 570 " " 

loco cent. cub. = 1 litre 

The residue from each section = 300 cent, cub., were united 
and analysed. 

ABC 

Nitric acid 1-2960 ? ? 

Sulphuric acid 0-2970 0-1240 0-1730 

Phosphoric acid 0-0750 0-0000 0-0750 

Lime 0-4104 0-1480 0-2624 

Magnesia 0-1398 0-0640 0-0758 

Potash 0-6131 0-2280 0-3851 

2-8313 0'5640 0-9713 

In the first of the following lines are placed the proportions of 
the matters given to the i)lants, calculated from column a ; in the 
second, the calculations are made from column o : — 

CaO KO SO3 

Given: -— - = 2-9; —— = 1-5; rr— : = 2-1 

MgO ' CaO ' MgO 

,, ^ , OaO KO SO3 

Absorbed: — -- = 3-4; — — = 1-5; — — = 2-2 
MgO ' CaO ' MgO 

II. Period. From June 12 to July 20. — At the commence- 
ment the plant weighed 65 grammes, and had nine leaves with a 
surface of 648 square centimetres ; water exhaled = 1 litre ; the 
plant received O'l gramme of phosphate of iron suspended in the 
water about the roots, the roots became of a reddish yellow colour. 

ABC 

Nitric acid 1-0800 ?. ? 

Sulphuric acid 0-2475 0-1704 0-0771 

Phosphoric acid 0-0625 0-0000 0-0625 

Lime 0-3420 0-1912 0-1508 

Magnesia 0-1165 0-0860 0-0305 

Potash 0-5110 0-3120 0-1990 

2-3595 0-7596 0-5199 

Proportions of bases and acids, — 

CaO „ ^ KO ^ ^ SO3 
Given: ^rF7^ = 2-9; ^^-x^-lS; rr-r = 2-1 

MgO CaO MgO 

*. T. . CaO ^^ KO ^ ^ SO3 
Absorbed: zf-x = 5-0; 777. = 1-3; r^-7; = 2-5 
MgO CaO MgO 

III. Period. From July 20 to 27. — At the commencement 
the plant weighed 73 grammes, and had eleven leaves with a sur- 



EXPERniENTS ON VEGETATION IN SOLUTIONS. 353 

foco of 720 square ccntimL'tres ; water exhaled = 1 litre ; to the 
solution was added O-l gramme of phosphate of iron ; radicatiou 
strong. This period differs from the preceding in the quantity of 
KOPOs given being double. 

ABC 

Nitric acid 1-OSOO ? ? 

iSulpliunc acid 0-2475 0-1716 O-OTnO 

Phosphoric acid 01250 0-0000 0-1250 

Lime 0-3420 0-1440 O'lDSO 

Magnesia 0-11G5 0-0860 0-0305 

Potash 0-551S 0-2160 0-3353 

2-4628 0-6176 0-7652 

Proportions of bases and acids, — 

CaO KO SOa 

Given: --- =2-9; -— - = 1-5; — -?• = 2-1 

MgO CaO ' MgO 

»x, 1 T CaO ^^ KO ^ SO3 

Absorbed: — — = 6-1 ; — - = 1-7: = 2-4 

MgO ' CaO ' MgO 

IV. Period. From July 27 to August 1. — At the commence- 
ment the plant weighed 147 grammes, had eleven leaves, with a 
surface of 1160 square centimetres; water exhaled = 1 litre; to 
the solution was added O'l gramme of phospiiate of iron ; the 
roots became distinctly reddish yellow. The plants received twice 
as much KOPO5 as in the second period. 

ABC 

Nitric acid 1-0800 ? ? 

Sulphuric acid 0-2475 01374 0-1101 

Phosphoric acid 0-1250 O-OOOO 0-1250 

Lime 0-3420 0-1188 0-2232 

Magnesia 0-1165 0-0719 0-0446 

Potash 0-5518 0-121)6 0-4222 

2-4628 0-4617 0-9211 

Proportions between bases and acids, — 

CaO KO SO3 

Given: ::7^-2-9; —^ = 1-6; rrr; - 2-1 

MgO ' CaO ' MgO 

., , , CaO KO SO3 

Absorbed: ^7-7- 5-0; 77-- = IS; rr^ = 2-3 
MgO ' CaO ' MgO 

To ascertain how far the results from this artificial mode of 
cultivation may be compared with those produced under natural 
circumstances, maize of tlie same kind was planted in the garden 
in the middle of May. The latter wore exposed to the same at- 
mospheric conditions as the experimental i)lants. On August 1, a 
plant from the garden of the same period of vegetation as the ex- 



354 APPENDIX E. 

perimental plant, with nho fifteen leaves, and visible male flowers, 
weighed 1260 grammes, that is to say, seven times as much as the 
artificially reared plant. The stem of the garden plant from the 
lower knot to the summit of the flower-stalk measured 150 centi- 
metres, being three times the height of the experimental plant. 

V. Period. From August 1 to 10. — At the commencement the 
plant weighed 173 grammes ; the stem was 52 centimetres high ; 
in the middle of the period the plant had fifteen large fine green 
leaves, with a surface of 1420 s(]uare centimetres. In this period 
double the quantity of water (2 litres) was exhaled, and as the 
older roots were distinctly I'eddish yellow in colour, the plant re- 
ceived no more phosphate of iron, but thrice as much phosphate 
of potash as in the second period. On August 6 and 7, the male 
flower, consisting of seven single ears, was fully expanded from 
the sheath, the stem was strong, and 70 centimetres high. On 
August 7, a fully formed female fiower appeared ; on August 9, the 
anthers began to shed their pollen. 

ABC 

Nitric acid I'OSOO ? ? 

Sulphuric acid 0'2475 

Phosphoric acid 0-1875 

Lime 0-3420 

Magnesia 0-1165 

Potash 0-5927 



0-1(540 


0-0835 


0-0020 


0-1855 


0-1236 


0-2184 


0-0790 


0-0370 


e-1894 


0-4033 



2-5662 0-5580 0-9277 

Proportions between bases and acids, 

CaO KO ^ SOa 

Given: = 2-9; = 1-7; ^ = 2-1 

MgO ' CaO ' MgO 

,, , , CaO KO SO3 

Absorbed: r--- = 5-9; 77-7: = 1-8; r-— = 2-3 
MgO ' CaO ' MgO 

As the plant in this period flowered, and earlier experiments 
had shown that maize dug up at the period of flowering, and 
placed in river water furnished still ripe seeds, and also by the ad- 
dition of the salts which the plant in each period had taken up in 
proportion to its increase in weight in the first four periods, it ap- 
peared that it must contain fully as much salts as the plant in its 
normal condition in the field takes up, if placed from this period 
only in distilled water. 

VI. Pei'iod. From August 10 to 16. — At the commencement 
the plant weighed 255 grammes, and had 15 fully expanded leaves 
with a surface of 2640 square centimetres : 2 litres of water were 
exhaled. 

On August 10, the anthers had almost completely shed their 
pollen. The stem shot up rapidly, and on the 12th it measured to 
the tip of the flower 1 metre in height. On the 13th a second 



EXPERIMENTS ON VEGETATION IN SOLUTIONS. 355 

female flower appeared, which was surrounded with paper to pro- 
tect it from dust. On August 10 the height of the plant was 
1-1 nii'tre ; it did not grow any more. The fruit-bearing stalk 
was, on August 10, already 2 decimetres long, aud had below a 
thickness of 4 centimetres. 

On August 10 the water was drawn oil" and analysed. 

Present. Not present. 

0016 gramme potash. Sulphuric acid (only indistinct opalos- 

0-008 " lime. cence with chloride of barium). 

0-001 " phosphoric acid. Magnesia. 

Iron and silicic acid. 

From the circtmistance that in this solution there was no silicic 
acid, it is plain that the glass vessel had furnished none to the Huid 
by decomposition in the course of one to two weeks. 

VII, Period. From August IG to September 4, — 

Weight of plant on IG August 280 grammes. 



22 " 


at 9 o'clock a.m. 31 G 


22 " 


" 9 " p.m. 320 


28 " 


" 9 " " 330 


1 Sept. 


" 9 " " 327 


4 " 


" 9 " " 317 



From September 1 the weight diminished by the drying of the 
leaves, and as this decrease was accidental, the plant was not 
thenceforward weighed. The leaves shrivelled. The plant had 
exhaled 3i litres of water in the period. At this time it was 
placed in a vessel containing 1-5 litres of water, to determine what 
salts returned to the water by endosmone. The water was kept 
up at the same level by daily additions, and at last was allowed to 
exhale until the residue was 1 litre. In this litre Avere found 0.031 
carbonate of lime, and 0.007 carbonate of magnesia. Both salts 
were left in the basin undissolved after evaporation, and after 
the residue had been treated with water. 

In the water with Avhich the residue left on evaporation in the 
basin had been extracted, the following substances were found in 
solution : — 

0*020 lime ( together with organic matter which 

O'OOOG phosphoric acid-/ reduced a solution of oxide of copper 
0'0034 potash ( and potash. 

In this last solution not a trace of iron, sulphuric acid or mag- 
nesia was found. As the preceding analyses indicate, the solution 
of nutritive matters for gramineaa must have the following com- 
position : — 

MgOSOs + 4CaON05 + 4K0N0.', + xKOPOs 

(Compare 'Chem. Central Blatt, 1801,' s. 405, 504, and 945.) 

* At all periods the plants threw oil" organic substances, but chiefly in the 
last periods. 



356 APPENDIX E. 



11. — Experiments of Stohmann. 

The experiments of Stohmann agree in their main results with 
those of Knop. According to these experiments, tlie maize plant 
grows to full maturity if in the beginning of May the seed which 
has germinated in water, and has shot forth roots, is placed in a 
solution containing the food of maize in tlie proportions in which 
they exist in the ashes, if at the same time there has been added 
to it so much nitrate of ammonia that to every part of phosphoric 
acid in the solution there are two parts of nitrogen, and if finally 
it has been diluted with distilled water to a concentration of three 
parts of solid juatter per 1000 parts. The plants must grow in 
a sunny spot, and the water exhaled by the leaves must be daily 
replaced by distilled water, and the solution tested as to its reac- 
tion. The solution must always react, slightly acid, and be main- 
tained in this condition by the addition from time to time of a few 
drops of phosphoric acid. If these conditions are fulfilled, there is 
no necessity for any artificial source of carbonic acid, but by means 
of the atmospheric carbonic acid alone there are produced fully 
formed plants which, under favoui-able cnxumstances, attain a 
height of 7 feet.* 

The experiments of Stohmann were more especially directed to 
the influence exercised on the growth of the maize jilant by the 
withdrawal of one element of food. In this point the results dilfer 
from those of Knop. Whilst in the experiments of the latter, 
maize was found to grow perfectly without silicic acid, soda, or 
ammonia, Stohmann made use of silicic acid in all his experiments, 
and found further that by the complete withdrawal of ammonia 
and even soda the plants grew quite well. 

On withdrawing ««»HOHZ« completely and replacing it by nitric 
acid, Stohmann found that the plants grew perfectly well for the 
first ten to twelve days, then they became of a pale yellowish 
green, and the vegetation proceeded extremely slowly. 

If after a month's vegetation a little ammonia (in the form of 
nitrate or acetate) was given to the plants, they died very quickly. 
Without this supply of ammonia the blanched, sickly vegetation 
continued ; the plant did not die, and yet it could not be said to 
live.t In the experiments made without soda^ it was found that 
the plant could dispense w' ith this substance at first, but its pro- 
gress was soon arrested if the soda was completely withdrawn, 
Tlie nitrate of lime of the normal solution was in another experi- 
ment replaced by a corresponding quantity of nitrate of magnesia. 
The growth of the maize plant was after a short time much re- 
tarded, only a few small, thin leaves being developed. By the ad- 
dition of a little nitrate of lime to the growing plant, the most 

* According to Knop maize plants growing in a watery solution give off 
carbonic acid continuously from their roots. 

t Compare Knop, ' Cliem. Central Bl. 1862,' s. 257. 



EXPERIMENTS ON VEGETATION IN SOLUTIONS. 357 

remarkable cliaiific was liowever produced. Sc.irccly li\o lumrs 
elai>seil before tlie fjrowth of the plant, wliidi had been stationary 
for four weeks, awakened to a new life, and proceeded from this 
time forth in the best manner possible. A plant without the after 
addition of nitrate of lime remained stationary, making no progress 
whatever: the maize plant, therefore, requires lime immediately 
after the comineneement of its growth. 

In an experiment in which the mrt^?ie.s'/« was replaced by nitrate 
of lime, the same result was obtained as when lime was wanting. 
In this case, also, the ve::etation was very poor. A supply of mag- 
nesia in the form of nitrate, exerted here also the most favourable 
action, only tho etl'ect was not so quickly produced as in the case 
of lime. 

Even by the complete withdrawal of nitric acid the maize 
plant did not grow. In these experiments it is true the alkalies, 
as well as the alkaline earths, were in part supplied in the form of 
sulphates and chlorides. Chlorine and sulphuric acid, however, 
are required only to a limited extent in the vegetable organism. 
The same holds good in the experiment without nitrogen. Ac- 
cording to these experiments, therefore, a plant is not developed 
if one of its elements of food is wanting, and the complete re- 
placement of one element of food by another one similar to it, is 
hence completely out of the question. The result may, however, 
be difterent with the reciprocal ^xo-^/V/Z replacement of similar ele- 
ments of food; and Stohmann is about to take up this question. 

The form in which the food was supplied was the following.* 
The silicic acid was always supplied in the form of silicate of pot- 
ash ; the potash as nitrate. In the series of experiments (3) which 
were made without nitric acid, sulphate of potash was used in- 
stead of the nitrate. 

The phosphoric arid was used in the form of 2N"aO, HO, POj-f- 
24HO ; in exi)erimental series 5, in which soda was excluded, a 
potash salt was used, 2K0, IIO, PO:,, of which a concentrated so- 
lution was prepared, containing a known quantity of potash and 
phosphoric acid. As the phosphate of soda contained more soda 
than was requisite in the composition of the ash, there was tlms in 
the duids in the experimental series 1 to Van excess of this base; 
at a later period, a correspondingly smaller (piantity of phosphate 
of soda and more of the potash salts were employed. 

The sulphuric acid was in the form of sulphate of magnesia, 
with the exception of 7, in which sulphate of ammonia was used, 
the magnesia required was added in the form of nitrate of mag- 
nesia. 

The oxide of iron was supplied in the form of pure sublimed- 

* To form a complete solution of all matters, ami to remove the alkalme 
reaction, the tlmd was first properly diluted with water and so much weak 
hydrochloric and later phosphoric acid was added as to make the reaction 
distinctly feebly acid. 



358 



APPENDIX E. 



clilorkle; tlie lime as nitrate, and in the case of 8 as cLloride of 
calcium; tlie ammonia as nitrate, sulphate, or chloride. 

It was scarcely possible to avoid using a larger or smaller ex^ 
cess of one or otlier of the substances. This was particularly the 
case with soda and chlorine. These deviations will be best shown 
in the following tables. 

Expenniciital xcrirs. 







1 


2 


3 


4 


5 


6 


7 




d 
■^ o 

f| 

o a 


a 

o 


li 




3 1^ 


C3 

1 

o 


a 
1 


•3 a 

.■a M 












^ 


^ 




Potash 


35-9 
1-0 

10-8 
6-0 
2-3 


35-9 

8-0 

10-8 

6-0 

2-3 


52-0 
8-0 

10-8 
6-0 
2-3 


35-9 
8-0 

10-8 
6-0 
2-3 


35-9 
8-0 

10-8 
6-0 
2-3 


35-9 

10-8 
6-0 
2-3 


35-9 
1-0 

13-7 
2-3 


35-9 


Soda 


1-0 


Lime 


19-2 


Magnesia 




Oxide of iron 


2-3 


Sulphuric acid .... 


5-2 


5-2 


5-2 


26-9 


26-9 


5-2 


5-2 


5-2 




1-3 

9-1 


19-7 
9-1 


3-1 
9-1 


66-5 
9-1 


16-S 
9-1 


3-1 
9-1 


3-1 
9-1 


3-1 


Phosphoric acid. . . 


9-1 


Silicic acid 


28-5 


28-5 


28-5 


28-5 


28-5 


28-5 


28-5 


28-5 




18-2 


18-2 


18-2 


— 


18-2 


18-2 


18-2 


l.s-2 







Summary of the weights of the crops. 



■3 


a 


Parts of plants. 


a 
S 


J3 
C3 

"o 

a 
3 


a 
< 


a 



a 
3 


a 


CS 

a 


'3 
6 


Proportion of 

the weight 

of the seed to 

th.at of the crop 

after deduction 

of the ash. 




From 
the 
gar- 
den. 

A 
B 




grms. 
10-361 
52-39 1 
42-39 1 
2S-51 J 
190-14 
22-66 
346-45 

3-921 

9-67 ! 
11-79 f 

4-91 J 
34-09 
64-38 
27-36 

4-24 
24-57 
56-17 


grms. 

15-24 

3-42 

0-54 

19-20 

S-97 

0-S2 
4-79 
4-35 
0-14 
0-56 
5-05 


per ct. 

11-4 

1-8 
2-4 
5-5 

13-1 

2-4 
7-5 
15-9 
3-4 
2-3 
8-9 


gi-ms. 

327-25 

59-59 
51-12 














— 




" of the head. 











1 


Entire plant 


1 : 3147 




Stem 








— 




" of heads . . . 
Head with grain . . 
Entire plant 


1:673 


















Entire plant . 


1 :491 



EXPEKIMENTS ON VEGETATION IN SOLUTIONS. 



359 







Summary of the 


weight.'! of t 


he crop 


f.— (C< 


ntinued.) 










« 


i 


Proportion of 


a V} 








c 






- 


tlic, weight 


E-g 


a 


Tarts of plants. 




.o 


o 


o 


V 


ol tho seed to 
that of the crop 










b 


3 
O 

a 


H 




after dediu'tioii 
of the ash. 


iA 








o 


< 


< 


O 












grms. 


grms. 


per ct. 


grms. 






c 


Entire plant 




65-52 


5-94 


10-7 


4y.5!S 


1 :477 


2. 


D 






(i2-44 


6-49 


10-4 


.10-9.5 


1 : 533 




A— C 


" " 




1-19 


— 


— 


— 


— 




D 


" " 




2-39 


0-54 


22-8 


1 -85 


1:13 


S. 


A— B 


" " 




0-204 


— 


— 


— 




4 


A 


Roots 




0-45 
1-03 


0-10 
0-17 


22-8 
16-7 


— 







Stem and leaves 











Entire plant . .. 




1-48 


0-27 


18-2 


1-21 


1 :12 




C 


'• " .... 




10-90 


0-92 


8-5 


9-98 


1 : 96 




D 


" " 


.. 


39-48 


5-57 


14-1 


33-91 


1 :326 


5. 


A 


" " 




49-63 


5-21 


10-5 


44-42 


1 : 427 




B 


" " 




32-Cl 


3-36 


10-4 


28-95 


1 : 278 


C. 


A 


" " .... 




0-30 


— 


— 


— 


— 




B 


« i< 


.. 


84-30 


8-22 


9-75 


76-08 


1 :731 


7. 


A 


" " 


.. 


0-82 


0-18 


21-4 


0-64 


1 : 6 




B. C 


" " ... 




6-01 


0-82 


13-7 


5-19 


1 : 50 



REMARKS ON THE SUMMARY OF THE WEIGHTS OF THE CROFS. 

I. Plants A, B, c, and p grew in normal solutions. Plants a and 
B were placed in the solution on .July 1, and plant a was gathered 
on September 10, fully ripened ; its total height was 202 centi- 
metres. The plant from the garden soil with which it was com- 
pared was of middle size. Plant n gathered on September 27, 
was fully grown, and had a height of 127 centimetres. Plants c 
and D were placed in the normal solution on June 10, they did 
not attain their full growth ; both were gathered on October 28. 

II. Commencement of experiment in solutions without ammonia 
on June 10. — a and n received on July 12 a supply of 0*2 gramme 
nitrate of ammonia ; on July 23 they were placed in afresh solution, 
to which was added 0-2 gramme acetate of ammonia ; both plants 
died on July 31. Plants c and d received normal solution on 
August 4, which was neutralised with phosphoric acid ; o died on 
August 9, D recovered somewhat, but remained sickly till gathered 
on September 27. 

III. E.xperiments icithont nitric acid. — Commencement on 
June 10; rapid decay of the plants; by July 1 a and c were al- 
ready dead. 

IV. Experiments tcithout nitrogen. — Commencement on June 
10. In the first week the growth was excellent, but in the second 



3G0 APPENDIX F. 

week it came to a stand, a lived till gathered on September 27 ; 
height 15 centimetres, length of roots 82 centimetres. Plants o 
and D received on July 11 each 0'2 gramme nitrate of ammonia, 
and on July 17, also, the same quantity. The iutiuence of this 
salt was rapidly visible. Ou August 4, o and d received normal 
solution. Plant c was gathered on September 27, height 75 centi- 
metres. Plant D, gathered on November 15, was in a liealtliy state, 
and had attained a height of 120 centimetres. 

V. Experiments toithout soda. — Commencement June 10. The 
early vegetation was very luxuriant ; in the end of July, however, 
the plants were not progressing. On August 4, the plants received 
normal solution ; two died, but a and b made farther progress. 
A and B were gathered on October 30, height of a, 205 centi- 
metres ; B stunted. 

VI. Experiments without lime. — Commencement June 10. 
Plant A had reached a height of 2 centimetres on July 17; but 
made no further progress, b received on July 1, O'l gramme lime 
in the form of nitrate, and on August 4, normal solution, vigor- 
ous growth. It had on November 15 four stems respectively 107, 
95, 75, 70 centimetres high, which were covered with leaves, and 
had eight well developed heads of fruit. 

VII. Experiments loitlwut maqnesia. — Commencement June 
10. Progress as in Experiment VI., and gathered as it was mak- 
ing no visible progress, b and c received on July 17, O'l gramme 
magnesia, and on August 4 normal solution, gathered September 
27; height of b, 23 centunetres ; of c, 42 centimetres. Both had 
male flowers without pollen, and no female flowers. 

On comparing his experimental plants with those which grew 
in the ground, both in respect to weight of the crop and to amount 
of ash and its composition, Stohmann concluded tiiat we may in- 
deed convert a plant of maize into a water-'plant., but that maize 
cannot grow in a normal condition in solutions of its food. Fur- 
ther, his experiments showed in a positive manner that the soil 
played a determinate part in the nutriment of plants — absorption 
of alkalies — and that plants in the absorption of their food must 
themselves take an active part (compare Henneberg's ' Journal fiir 
landwirthschaft, 1862,' s. 1. and 'An. der Chem. uud Pharm.,' bd. 
cxxi. s. 285). 



APPENDIX F (pp. 114, 115). 

EXPERIMENTS ON THE GROWTH OF BEANS IN POWDERED 
TURF. 

To complete the experiments on vegetation described at page 
112, the results of the entire crops are now given in the following 
table : — 



EXPEKIMENTg ON THE GKOWTH OF BEANS. 



361 



Dry substance of tlic bean plants in ffrantmcs. 





I. Pot, 

fully 

saturated. 


II. Pot, 

half 

saturated. 


III. Pot, 

quarter 

saturated. 


IV. Pot, 
pure 
turf. 


Seed 


93-240 
25-948 
19-420 
26-007 
58-399 


66-127 

18-393 
15-797 
20-107 
36-368 


• 50-463 
13-658 
12-477 
15-710 
25-411 


7-069 


Shell 


2-631 


Leaves 


1-979 


Stem 


5-676 


Roots 


3-063 






Total weight 


223-014 


156-792 


117-719 


20-418 



These nnmbers completely confirm the conclusions drawn from 
the weight of the seeds alone. If the crop from the pure turf be 
taken as unity, the weights of the entire crops bear the following 
proportions — 

1:5-7: 7-7 : 10-9 

or if the weight of the crop in the J saturated tnrf be called 2, and 
that of the -^ and fully saturated turf be compared with it, the fol- 
lowing proportions are found — 

2:2-7: 3-8 

If the weight of the crop furnished by the pure turf be sub- 
tracted from each of the others, and the weight of the crop in tho 
J saturated turf be taken at 2, then the crops in the ^ and fully 
saturated turfs bear the following proportions to it — 

2:2-8: 4-2 



APPENDIX G (page 229). 

Extract from the Report to the Minister of AgricuUitre at Berlin, 
on Japanese Ilusbandry ; hy De. H. Maeon, Member of the 
Prussian East Asiatic Expedition. 



SECTION I. 

SOIL AND MANURING. 



The Japanese empire stretches from the 30th to the 45th de- 
gree of north latitude. The average temperature and distribution 
of heat constitute a climate embracing all the gradations between 
those, of central Germany and of Upper Italy. A solitary tropical 
palm, not fully developed, grows by the side of the northern pine, 



362 APPENDIX G. • 

rice and cotton along with buckwheat and barley. Everywhere 
on the chains of hills, which cover the whole country like an ir- 
regular tine network, the piue predominates, stamping upon the 
landscape that homely northern character, which atfords so clieer- 
ing a sight to the northern traveller, w ho reaches these shores after 
having passed through the hot and luxuriant regions of the tropics. 
In the valleys, on the other hand, the burning south holds sway, 
covering the ground with a rich vegetation of rice, cotton, yams, 
and sweet potatoes. Hundreds of footpaths and small ravines lead 
to charming transitions between pine and cotton, hill and dale ; 
everywhere there is a gay medley of laurels, myrtles, cypresses, 
and above all, shining camellias. 

The land is of volcanic origin, and the entire surface belongs 
to the tufa and the diluvium formation. The soil on the hills con- 
sists of an extremely fine, yet not over fat brown clay ; whereas 
that of the valleys is throughout the country, with some trifling 
modifications, of a black, loose, and deep garden mould, which 
upon trial in different places I found extended to a depth of 12 to 
15 feet, being throughout of the same quality, though somewhat 
more compact in the deeper layers. An impermeable stratum of 
clay probably underlies this arable crust. As the clay strata of the 
mountains, in consequence of the frequent and copious falls of rain, 
give rise to a multitude of springs, which are everywhere at hand, 
and may thus easily and without any great skill, be turned to ac- 
count for the purpose of irrigation ; so the impermeability of the 
stratum underlying the surface soil in the valleys enables the Jap- 
anese husbandmen to turn the soil at pleasure into a swamp, for 
the cultivation of rice. 

Whichever way one may feel inclined to decide the question, 
whether the present fruitfulness of the soil is simply the artificial 
product of cultivation continued for a period of several thousand 
years, or whether this fertility existed from the beginning, making 
this people love and cherish the labours of agriculture, this much 
must be granted, at all events, that the clay of the diluvium, the 
mild climate, and abundance of water, afforded all the conditions, 
and the most convenient means, for a thriving cultivation. All 
these advantages have been most carefully turned to account by 
an industrious, ingenious, and sober people ; and husbandry in 
Japan has become a truly national occupation. The Japanese 
have thoroughly mastered the difficult task of maintaining .agricul- 
ture in a state of the highest perfection, although its pursuit is en- 
tirely in the hands of peasants and yeomen, who take rank in tli& 
sixth and last but one class of the social scale, and no Japanese 
gentleman is a farmer. There are no agricultural institutions for 
instruction in husbandry, no agricultural societies, no academies, 
no periodical press to spread the teachings of science. The son 
simply learns from the father ; and as the father knows quite as 
much as his grandfather and great grandfather before him, so he 



JAPAITESE HTISBANDRT. 363 

pursues exactly the same system of Imsbandry as any other peasant 
in any other part of tlic empire ; but it is a matter of perfect in- 
difference where the young agriculturist learns his business. The 
young pupil in husbandry will always be able to master a certain 
small amount of information which the experience of ages has 
shown to be true, so that it may be looked upon as positive knowl- 
edge, and a sort of hereditary heirloom. 

I must confess that I experienced a feeling of deep humiliation 
on many occasions, when with this simple knowledge, and the safe 
and nncontested practical application of it in Imshandry before my 
eyes, I thought of home. We boast that we are a civilized nation ; 
in our land men of the highest intellectual attainments devote 
their best energy to the improvement of agriculture; we have 
everywhere agricultural institutions and agricultural societies, 
chemical laboratories and model farms, to increase and diffuse the 
knowledge of husbandry. And yet how strange that, despite all 
this, we still go on disputing, often so vehemently and acrimo- 
niously, about tlie first and most simple scientific principles of agri- 
culture ; and that those who earnestly search after truth are forced 
to admit the infinite smallness of their positive and undisputed 
knowledge! How strange also that even this trifling amount of 
positive knowledge has as yet found so little ai^plication in prac- 
tice! 

Among the great questions which still remain in dispute with 
us, whilst in Japan they have long since been settled in the labo- 
ratory of an experience extending over thousands of years, I must 
mention as the most important of all, that of manuring. The edu- 
cated sensible firmer of the old world, who has insensibly come 
to look upon England, with its meadows, its enormous fodder 
production and immense herds of cattle, and in spite of these with 
its great consumption of guano, ground bones, and rajie-cake, as 
the beau ideal and the only possible type of atruly rational sys- 
tem of husbandry, would certainly think it a most surprising cir- 
cumstance to see a country even much better cultivated, without 
meadows, without fodder production, and even without a single 
head of cattle, either for draught or for fattening, and without the 
least supply of guano, ground bones, saltpetre, or rape-cake. This 
is Japan. 

I cannot help smiling when I remember how', on my passing 
through England, one of the great leaders of agriculture in that 
country, pointing to his abundant stock of cattle, endeavoured with 
an authoritative air to impress upon my mind tlie fillowing ax- 
ioms, as the great secret of true wisdom : — ' The more fodder, the 
more flesh'; the more flesh, the more manure ; the more manure, 
the more grain ! ' The Japanese peasant knows nothing of this 
chain of conclusions ; he simply holds fast to one indisputable 
axiom, viz. without continuous manuring there can bo no continu. 
0U3 production. A small portion of what I take from the soil is 



3G4 APPENDIX G. 

replaced by nature (the atmosphere and the rain), the remainder I 
must testore to the ground ; the manner in which this is done is a 
matter of indifference. That the produce of the land has first 
to pass through the human body before it can be returned to the 
soil, is, as far as manuring is concerned, simply a necessary evil, 
which always involves a certain loss. As to the intermediate stage 
of cattle feeding, which we deem so requisite in our system, the 
Japanese farmer cannot at all see its necessity. He argues in his 
way that it must cost a great deal of unnecessary and expensive 
labour to have the produce of the field first eaten by cattle, so 
troublesome and expensive to breed, aud that this system must in- 
volve more considerable loss of matter than his own. How much 
more simple it must be to eat tlie corn yourself, and to produce 
your own manure ! Far from me be it, however, upon the ground 
of the so widely ditfering results to which the developement of 
agriculture has led in the two lands, to pass judgement upon our 
system of husbandry, and to exalt unduly that of the Japanese by 
attributing superior intelligence to that nation. Circumstances 
have brought about the results in question, and the following more 
especially have exercised a decided influence in the matter. The 
religious belief of the two great sects in Japan, the Sintoists and 
the Buddhists, forbids the eating of flesh, and not alone of flesh, 
but of everything derived from animals (milk, butter, cheese) ; this 
prohibition, of course, disposes of one of the principal objects for 
which cattle are bred. Even sheep, if kept for the wool alone, 
would not pay, as our farmers begin to find out even in Germany. 

The very limited area of the homesteads in Japan also makes 
the maintaining of cattle superfluous. The smallness of the farms 
must not be attributed, however, to any excessive tendency to sub- 
division of lauded property, biit to the fact that the land belongs 
to the great princes or Daimios of the country, who have bestowed 
it in fee upon th^ lower nobility. The latter, again, being pre- 
cluded by the institutions of the country from farming their own 
estates, have parcelled the land out, apparently from time imme- 
morial, on perpetual leases, among the peasantry of the country. 
The size of these farms varies from two to five acres ; the limita- 
tion having been most likely determined either by their natural 
position, or from the course of some brook or rivulet. Now, as 
this limited area is intersected moreover by drains and ditches, it 
will be readily seen that there is hardly a plot of ground to be 
found where the use of beasts of burden might be profitably had 
recourse to. 

Now, with us matters are very diiferent in these respects. We 
have a notion that we could not possibly exist in health and vigour 
without a considerable consumption of meat, although we liave 
the ftict constantly before our eyes, that our labourers, who assur- 
edly require as much strength as any other class of society, are, 
for the most part, involuntary Buddhists. Our farms are always 



JAPANESE HUSBANDKT. 365 

sufficiently largo to preclude the notion of working them by hand, 
even leaving out of consideration the important circumstance that 
the price of labour is rather too high, iu proportion to the value of 
the produce, to admit of such a system of farming. But that the 
culture of the Sdil is everywhere in the world indirect ratio to the 
division of the land is a well-established fact, of whicli the reality 
and significance are made most clearly apparent to the traveller 
who passes from the north of Germany to Japan, via England. 

The only numure-prodncer, therefore, in Japan is man ; and 
we need not wonder tliat the greatest care should be bestowed in 
that country upon the gathering, preparing, and applying his ex- 
crements. Now, as their entire course of proceeding contains 
much that is highly instructive for us, I consider it my duty to 
give as detailed a description of it as possible, even at the risk of 
ofien'Sing the delicate feelings of the reader. 

The Japanese does not construct his privy as wq do in Ger- 
many, in some remote corner of the yard, with half-open rear, 
giving free admission to wind and rain ; but he makes it an essen- 
tial part of the interior of his dwelling. As he ignores altogether 
the notion of a 'seat,' the cabinet, which, as a general rule, is very 
clean, neat, and, in many cases, nicely papered or painted and var- 
nished, has a simple hole of the shape of an oblong square running 
across and opposite to the entrance door, and serving to convey the 
excrements into the lower space. Squatting over this hole, with 
bis legs astride, the Japanese satisfies the call of nature with the 
greatest cleanliness. I never saw a dirty cabinet in Japan, even in 
the dwelling of the very poorest peasant. It appears to me that 
there is something very practical in this form of construction of a 
closet. We, in Germany, construct privies over our dung-holes, 
and behind our barns, for the use of our farm-servants and labour- 
ers, and X)rovide them with seats with round holes. With even 
only one aperture, it is too often found that after a few days' use 
they look more like pigstyes than closets for the use of man, and 
this simpl}^ because our labourers have a decided, perhaps natural, 
predilection for squatting. The construction of the Japanese privies 
shows how easy it would be to satisfy this predilection. 

To receive the excrements, there is ])laced below the squai'e 
hole a bucket or tub, of a size corresponding to it, with projecting 
ears, through which a pole can be passed to carry the vessel. In 
many instances a large earthen pot, with handles, is used, fur the 
manufacture of which the Japanese clay supplies an excellent mate- 
rial. In some rare instances in the towns, I found a layer of chop- 
ped straw or chaff at the bottom of the vessel, and occasionally 
also interspersed among the excrements, a proceeding which, if I 
mistake not, has of late been recommended also in Germany. As 
soon as the vessel is full, it is taken out and emptied into one of 
the large dung-vessels. These are placed either in the yard or 
in the field. They are large casks or enormous stoneware jars, in 



366 APPENDIX G. 

capacity of from 8 to 12 cubic feet, let into the ground nearly to 
tlie brim. It is in these vessels that the manure is prepared for 
the field. The excrements are dilated with water, no other addi- 
tion of any hind being made to them, and stirred until the entire 
mass is worked into a most intimately intermixed fine pap. In 
rainy weather, the vessel is covered with a moveable I'oof to shield 
it from the rain ; in dry weather this is removed, to allow the 
action of the sun and wind. The solid ingredients of the pap grad- 
ually subside, and fermentation sets in ; the water evaporates. By 
this time the vessel in the privy is again ready for emptying. A 
fresh quantity of water is added, the whole mass is again stirred 
and most intimately mixed together, in short, treated exactly like 
the first emptying. Tlie same process is repeated, until the cask 
or pan is full. After the last supply of excrements, and thorough 
mixing, the mass is left, according to the state of the weather, for 
two or three weeks longer, or until it is required for use ; iut under 
no circuinstancG is the manure ever em2)loyed in the fresh state. 
This entire course of proceeding clearly shows that the Jap- 
anese ARE NO partisans OF THE NITROGEN THEORY, AND THAT THEY 
ONLY CARE FOR THE SOLID INGREDIENTS OF THE DUNG. They IcadC 

the ammonia exposed to decomposition hy the action of the sun, and 
its volatilisation hy the wind, but trihe the greater care to shield the 
solid ingredients from being loasted or sicept awccy by rain, &c. As 
the peasant, however, pays his rent to liis landlord not in cash, but 
in a certain stipulated percentage of the produce of his fields, he 
argues quite logically that the supply of manure from his privy 
must necessarily be insuflicient to prevent the gradual exhaustion 
of the soil of his farm ; notwithstanding the marvellous richness 
of the latter, and in spite of the additional supply of manuring 
matter derived from the water of the brook or canal from which 
he takes his material for irrigation. He places, therefore, wher- 
ever his field is bordered by public roads, footpaths, &c., casks or 
pots buried in the ground nearly to the rim, urgently requesting 
the travelling public to make use of the same. To show how 
universally the economical value of manure is felt and appreciated 
in all classes of society in Japan, from the highest to the lowest, I 
i>eed simply state the fact that, in all my wanderings through the 
country, even in the most remote valleys, and in the homesteads 
and cottages of the very poorest of the peasantry, I never could 
discover, even in the most secret and secluded corners, the least 
trace of human excrements. How very different with us, in Ger- 
many, where it may be seen lying about in every direction, even 
close to privies ! 

I need not mention that the manure thus left by benevolent 
travellers is treated exactly in the same way as the family manure. 

But the excrements of the peasant contain also some other 
matter, which has not been derived from the soil of his fields, and 
which may be said to represent an additional importation of ma- 



JAPANESE HUSBANDRY. 367 

nuro. The river, brooks, and canals, and the numerous littlo 
bays, abound in fisli, which the religion of the Japanese pcrinits 
him to eat, a permission of which he most largely avails himself. 
Fishes, crabs, lobsters, and snails are eaten in quantities, and these 
ultimately atlord a most valuable item of contribution to the privy, 
and consequently to the fertilising iield-manure. 

The Japanese former prepares also compost. As he keeps no 
cattle to turn his straw, &c., into manure, he is forced to incorpo- 
rate this part of his produce with the soil without ' animalisation.' 
The method pursued to effect this object consists simply in the 
concentration of the materials. Chaff", chopped straw, horse-dung, 
excrement gathered in the liighways, tops and leaves of turnips, 
peelings of yams and sweet potatoes, and all the oft'al of the farm, 
arc carefully mixed with a little mould, shovelled up in small 
pyramidal heaps, moistened and covered with a straw thatch. I 
often saw also in this compost heaps of shells of mussels and 
snails, with which most of the rivulets and brooks abound, and 
which, in all parts close to the seashore, may be obtained in any 
quantities. The compost heaps are occasionally moistened and 
turned with the shovel, and thus the process of decomposition 
proceeds rapidly, under the powerful action of the sun. I have 
also often seen the shorter process of reduction by fire resorted to 
when there was plenty of straw, or where the manure was required 
for use before it could be got ready by the fermentation process. 

The half-charred mass was, in such cases, in so far as my own 
observation enabled me to judge, strewed directly on the seed 
sown in the ground. 

I think the treatment of this compost is another proof that the 
Japanese farmer does not care for the azotised matters, and that 
he strives to destroy all organic substances in his manure before 
making use of it. TTie great ohject of the Japanese fanner in all 
this is to turn Jiis manure to account as frompthj as 'possible. 

To attain this end, besides preparing his manures in the man- 
ner described, he has recourse also to the following means : — 

1. He applies his manures, and particularly his chief manure 
derived from his privy, invariably as much as possible in the liquid 
form. 

2. lie hnoics no other mode of manuring than that of top- 
dressing. 

"When ho wishes to sow, the land is laid in furrows, in the way 
to be more fully described hereafter, and the seed is strewn by 
hand, and covered with a thin and even layer of compost, over 
which liquefied and very dilute privy manure is i)oured. Tlie 
manure is diluted in the buckets in which it is carried from the 
preparing tubs or pots to the seed furrow, as this is tiio only way 
to ensure uniform intermixing of the materials. As this manure 
lias fully fermented, it may without danger be brought into hunie- 
diate contact with the seed, and thus materially assist the first 
radication. 



368 APPENDIX G. 

It may be that tins Japanese system of manuring cannot as yet 
be introduced into Europe in its integrity. But with such excel- 
lent results to show for their proceedings, we might surely take a 
few lessons from these old practical men, and employ them with 
such modifications as our social relations require. At all events 
we might adopt in principle the following : — 

1. The greatest possible concentration of manures, which must 
necessarily lead also to a material reduction of cost. When I 
stated that the Japanese does not trouble himself about the azo- 
tised matters in his manures, and that his land is, notwithstanding, 
in a most flourishing state of culture, this is no proof, however, 
that it might ?iot even ie Ifetter, perhaps, to endeavour to fix the 
nitrogen too. If a more practical system can be devised, of which 
however I have my doubts, combining the advantage of both, so 
much the better! But till something better is discovered, we 
might surely adopt that which experience has jiroved to be good. 

2. Top-dressing, which is of course necessarily connected with 
cultivation in drills or furrows. 

3. Liquid manuring: not to the extravagant extent, however, 
in which it was sought to be carried out in England, but in accord- 
ance with the present condition of German agriculture. 

4. Manuring with every crop. 

The Japanese never cultivates a crop without manuring it, but 
he gives each crop or seed exactly as much and no more manure 
than is required for its full developement. He docs not care about 
enriching the soil for future crops. "What lie demands is simply a 
full crop in return for each sowing. How often do we hear our 
farmers talk about this manure being preferable to that manure on 
account of its fertilising action being 'more lasting;' yet with all 
our wise provision for the future, how far are we now behind the 
Japanese, who seem to look always to the next harvest only ! As 
they manure for each fresh crop, and the term ' fallow' in our ac- 
ceptation is entirely unknown to them, they are forced to distrib- 
ute their yearly production of manure equally over the entire area 
of their land, which can be accomplished only by sowing in drills 
or furrows, and by top-dressing. 

The contrast between this rational system and the profuse ap- 
plication of our long straw manure over the Avhole surface of the 
field is truly glaring. 

I may also add here that the manure in the Japanese towns is 
never artificially turned into guano or poudrette, but is sent every 
night and morning in its natural form into the country around, to 
return again after a time in the shape of beans or turnips. Thousands 
of boats may be seen early each morning laden with high heaps of 
buckets full of the precious stufl^, which they carry from the canals 
in the cities to the country. These boats come and go with the 
regularity of the post ; it must be admitted, however, that it is a 
species of mai'tyrdom to be the conductor of a mailboat of this 



JAPANESE HUSBANDRY. 369 

kind. In tho evening long strings of coolies arc met with on the 
road, who having in tho morning carried tho produce oi tho coun- 
try to the town, are returning homo each witli two buckets of ma- 
nure, not in a solid or concentrated form, but fresh from tho privies. 
Caravans of packhorses, which often have brought manufactured 
articles (silk, oil, lacquered goods, &c.), a distance of 200 to 300 
miles from tho interior to the capital, are sent homo again freighted 
with baskets or buckets of manure ; in such cases, however, care 
is taken to select solid excrements. 

Thus in Japanese agriculture we have before ns tho represen- 
tation of a perfect circulation of the foi'ces of nature : no link in 
the chain is over lost, one is always interlaced with the other. 

I cannot refrain here from drawing a parallel in this respect 
between the Japanese and our system. In our large farms we sell 
a portion of tlie productive power of our soil in the form of corn, 
turnips, or potatoes ; but our carts which convey the products to 
the town or to the gates of the factory, bring back no compensa- 
tion. One of the links of tho chain is lost. There is another por- 
tion of our produce devoted to tho feeding of large herds of cattle, 
of which a considerable amount is sent forth in the form of fat 
cattle, milk, butter, or wool ; this again is never returned, and 
thus a second link of the chain is lost. Another small portion we 
and our labourers consume. This last portion at least mi(jlit be 
turned to proper account, if we only knew, like the Japanese, to 
save and use it more carefully and wisely. Will any one venture 
to assert that tho privy manure of our farms is of the least real 
importance ? I verily believe that, under present circumstances, 
the privy manure of an estate of a thousand acres would be barely 
sufficient for half an acre of ground. There remains, then, from 
our present agricultural system, out of the entire productive power 
withdrawn by the crops from the soil, only that portion returned 
by our cattle, a small part indeed of tlie whole, if we take into 
consideration its bulk, and reflect in how concentrated a form we 
have disposed of the rest of that power in the shape of grain, milk, 
or wool. 

It may be objected, I am quite aware, that it is strange that 
our system of keeping large stocks of cattle does succeed in lead- 
ing to a high state of cultivation and abundant produce. I admit 
the fact, only lot us ascertain first its true significance. It is, above 
all, necessary to settle about the true acceptation of tho term 'cul- 
ture.' If by ' culture ' is meant the capability of the soil to give 
permanently high produce, by way of real interest on the capital 
of the soil, I must altogether deny that our farms (with perhaps a 
few exceptions), can properly bo said to bo in a satisfactory state 
of culture. But we have by excellent tillage and a i)eculiar meth- 
od of manuring, put them in a condition to make the entire pro- 
ductive power of the soil available, and thus to give immediately 
full crops. It is not, however, the interest that wo obtain in such 



370 APPENDIX G. 

crops, but the capital itself of the soil upon "which we are drawing. 
The more largely our system enables us to draw upon this capital, 
the sooner it will come to an end. The term ' culture ' applied to 
such a proceeding is a misnomer. The peculiar method of ma- 
nuring alluded to consists merely in our endeavouring to feed the 
soil of our fields with the largest possible supply of azotised mat- 
ter. Now, ammonia and the other azotised compounds may no 
doubt be looked upon as excellent agents to stir up the hidden and 
slumbering forces of the soil. But after all, these agents may be 
regarded somewhat in the light of a banker, who kindly exchanges 
the pound we have to spend for thirteen shillings ; and then we 
can spend the change fast enough. This accounts for tlie large 
party amongst us wlio love and cherish the obliging banker. 

This is the great difference between European and Japanese 
culture. The former is simply a delusion, which will be detected 
sooner or later. Japanese cultivation, on the other hand, is actual 
and genuine ; the produce of the land represents indeed the inter- 
est of the capital of the soil's productive power. As the Japanese 
knows that he has to live upon that interest, his first care is de- 
voted to keeping the capital intact. lie only takes away from his 
soil with one hand, if he can make up the loss with the other ; 
and he never takes more than he can return. He never endeavours 
to force the production by large supplies of azotised matters. 

The fields in Japan do not, therefore, as a general rule, present 
that luxuriant aspect which gratifies our sight occasionally at 
home. There are no impenetrable forests of straw from six to 
eight feet high, to be seen, nor turnips weighing 100 lbs., with 
99 lbs. of water in them. There is nothing extravagant in the 
sight of Japanese crops. But what distinguishes them most favour- 
ably as comfareil to ours is their certainty and uniformity for thou- 
sands of years. The real produce of land can de calculated only hy 
the average cro^is of a long numher of years. 

If additional proof were needed to show that the state of culti- 
vation is very superior, and that the land yields abundant produce, 
I would point to the fact that the Japanese empire, which covers 
an area similar to Great Britain and Ireland, and of which one- 
half at the most, from the hilly nature of the country, can be looked 
upon as fit for tillage, not only contains a larger number of inhab- 
itants than Great Britain and Ireland, but maintains them without 
any supply of food from other parts. Whilst Great Britain is 
compelled to import corn from other countries, to the extent of 
many millions per annum, Japan since the opening of its ports 
actually exports no inconsiderable quantities of food. 

SECTION II. 

TILLAGE OF THE SOIL. 

Deep cultivation of the soil has become a kind of proverb with 
our modern v/riters on agriculture ; and the principle of the eys- 



JAPANESE HTJSBANDKY. 371 

tern is, at Icnst, fully adinittcd on all hands, the only objection oc- 
casionally raised against it lieing that it requires a large supply of 
manure. Ihit the most enthusiastic admirer of the system in 
Europe can hardly conceive how universally and in what high per- 
fection it is carried on in Japan. 

The Japanese hiisbandmau has come to treat his field as a 
plastic material, to be turned to account in any way or forni he 
pleases, just as a tailor may cut out of a piece of cloth, cloaks, 
coats, trowscrs or vests, and occasionally makes the one out of the 
other. To-day we find a plot of ground covered with a wheat 
crop ; in eight days the wheat is reaped, and one half of the field 
is transformed into a swamp thoroughly saturated with water, in 
which the fiirmer, sinking up to his knees, is'busy planting rice, 
whilst the other half is a broad and dry plot, raised 2 or 2^ feet 
above the rice swamp, and ready to receive cotton, or sweet pota- 
toes, or buckwheat. It often happens also that a square plot in 
the centre is turned into a dry bed, surrounded by a broad rice 
swamp ; and as the water must cover the surface of the latter 
only slightly, the levelling must have been efiected with great 
care, and with the use of instruments. 

The whole of this work has been done by the farmer and bis 
small family in a very short time. That it could be accomplished 
in so short a time is a proof of the great depth of the loose arcthle 
soil, even after a harvest; and that the farmer could venture to do 
so without troubling himself about the next crop, is a sign of the 
nhoiuuUnfj iceedth of the soil in mineral constituents. It is only 
when great depth of the loose arable soil is combined with a plen- 
tiful store of mineral constituents that deep tillage of the ground 
can truly be resorted to. The description here given is not a mere 
fiction or creation of the imagination, but a faithful statement of 
facts such as I have had occasion to witness by the hundred. 
Considering that rice requires at least from 1 to li feet of cultivated 
soil, and adding to this half the height of the raised bed, viz. 1 to IJ 
feet, this gives a cultivated depth of arable soil of from 2 to 3 feet. 

This system of working the land at pleasure either as a raised 
dry jdot or as a swami), is indeed, at present, in Japan, simply a 
proof of the existence of deep tillage ; but it is clearly evident that 
it must have been, at one time, also, the means of effecting it. If 
we are always to wait until we have collected a sutficieut excess 
of manure (at the best but a very relative term), before proceeding 
to deepen the arable crust of onr land, we may certainly i)redict 
that the system will but very rarely make any progress with us. 
Everybody knows that one caimot learn to swim without going 
into the water. 

The introduction and constant ])rogress of tlie system of deep 
tillage have been powerfully assisted in Japan by the practice pur- 
sued from time immemorial of growing all crojis in drills. With 
the advantage of this niethnd we have also long been familiar. 



372 APPENDIX G. 

Among the favourable features presented by the cultivation of root 
crops, our books of agriculture always place in a prominent rank 
the fact that it enables the farmer to deepen the arable soil of his 
land. All our gardeners, at least, have long ago adopted it. 

I was not fully aware of the true importance of tlie method of 
growing crops in drills, until I had occasion to see it carried out 
to the fullest extent in Japan. "We, in Europe, are as yet far from 
having adopted this plan as an essential part of our system of hus- 
bandry; we look upon the question still in a very one-sided 2^oint 
ojvieiD, only in reference to the individual crop whicJi toe wish to 
grow. But the Japanese farmer has raised it to the rank of a sys- 
tem, by "which he has fully emancipated himself from the neces- 
sity of paying, as we are compelled to do, the least regard to the 
rotation of crops. By its means he has truly become master of his 
land. He has not only succeeded in growing crops at the same 
time which used to follow each other, but ho has carried to the 
highest perfection the principle of mixed cultivation, which begins 
now to find favour also with our European farmers : he has, in this 
respect put an end to our confused and haphazard way of mixing 
crops on the same field, having by the adoption of the method of 
drill planting, brought order and regularity into the system. The 
following description of the Japanese system may serve by way 
of illustration. 

"We have a Japanese field before us, in the middle of October, 
with nothing but buckwheat upon it. The buckwheat is planted 
in rows, 24 to 26 inches apart ; the intervening, now vacant, space 
had been sown in spring with small white turnip-radishes, which 
have already been gathered. These intervening vacant spaces are 
now tilled with the hoe to the greatest depth attainable by the im- 
plement. A portion of the fresh earth is raked from the middle 
up to the buckwheat, which is now in full flower : a furrow is thus 
formed in the middle, in which rape is sown, or the grey winter 
pea, the seed being manured in the manner already described, and 
seed and manure afterwards covered with a layer of earth. "By the 
time the rape or the peas have grown one to two inches high, the 
buckwheat is ripe for cutting. A few days after the rows in 
which it stood are dug up, cleared, and sown with wheat or win- 
ter turnips. Thus crop follows crop the whole year through. The 
nature of the preceding crop is a matter of inditference, the selec- 
tion of the succeeding one being determined by the store of ma- 
nure, the season, and the requirements of the farm. If there is a 
deficiency of manure, the intervening rows are allowed to lie fal- 
low, until a sufl[icient quantity has been collected for them. 

This system, as a whole, has also this great advantage, that 
the manure may be used at all times, and need never lie idle as a 
dead capital bearing no interest ; and moreover, perhaps, the most 
important point of all is, that a direct ratio is thereby secured be- 
tween the power of the soil, as shown in the crops, and the stock 



JAPANESE HUSBANDRY. 373 

of manure on hand, a ratio not disturbed here by artificial means 
or hy any ^ tour de force.'' Expressed in other words, the in- 
come and expenditure of t!ic soil arc always kept evenly bal- 
anced. 

I have seen this system carried out to the fullest attainable 
degree in the vicinity of large towns, such as Jeddo, also in par- 
ticularly fertile valleys, and on lields bordering on the great high- 
ways. Here crop succeeded crop, manure followed manure. 
Here the plot of ground produced much more than could be con- 
sumed on it ; but the great city and the privies on the high road 
returned a supply of manure to balance the export of produce. 

I have, however, also had occasion to visit farms situated on 
some hilly part far away from the high road, and only recently 
reclaimed and cultivated. As the Japanese farmer, as a general 
rule, prefers the valleys to the hilly ground, the sujjply of manure 
here is more restricted and more difficult, and any addition to it 
from towns or by travellers is almost altogether out of the ques- 
tion. Here I found occasionally only one crop on the ground ; 
yet the rows were so wide asunder that another crop would have 
found ample space between them. With this system it is at least 
possible to till properly and repeatedly the intervening spaces, 
wliich are intended to receive the next crop ; besides the constant 
Bupply of fresh earth to the present crop, by raking, places a 
larger store of soil at the disposal of the latter than cftuld be done 
in any other way. In this manner only the one-half of the field 
(corresponding to the limited supply of manure) is actually made 
to produce ; but the system of planting the crop in drills wide 
asunder always gives a much more abundant return than could 
possibly be obtained, if the one-half of the field as a continuous 
plot were completely sown, the other half being allowed to lie 
fallow. As the home production of manure or the importation of 
it from other parts, increases, the farmer proceeds to fill part also 
of the vacant rows, which thus leaves only the third or fourth 
part of the field fallow, until, at last, evei-y row is made to produce 
crops. 

How wide the difference between this system and ours! 
"When we break up and till a plot of ground, Ave begin by extract- 
ing from it three or four harvests, without bestowing a particle of 
manure, and apply manure only when the soil is exhausted. 
The Japanese Imnhandman never breals np a plot of land, vnlcss he 
jiossesses a small stock of manure, which he may invest in the 
ground ; and even then he only cultivates this new plot to the ex- 
tent his supjdy of manure will permit. This rational proceeding 
shows the deepest insight into the nature of the system of agri- 
culture to be pursued with a reasonable prospect of securing a 
constant succession of remunerative crops. No other illustration 
can so clearly show the ditierence between our European way of 
viewing the matter and the Japanese. We, in Europe, cut down 



374 APPENDIX H. 

the trees on a forest plot, sell the timber, grub up, plough and till 
the ground, and then proceed to dispose of the productive power 
of the new soil, in three cereal crops, obtained without the least 
supply of manure ; or we may possil)ly assist in accelerating the 
exhaustion of the ground by a small dose of guano. All that this 
course of proceeding is calculated to accomplish is, that we have 
now to distribute the manure hitherto produced on our estate over 
a somewhat more extended surface than formerly. When the Jap- 
anese husbandman breaks up a plot of gi'ound, he finds a virgin 
soil, the productive power of which he has not the least intention 
of impairing. He therefore, from the very outset, takes care to 
establish a proper balance between crop and manure, expenditure 
and income, maintaining thus intact the productive power of the 
ground, which is all that can reasonably be attempted by any ra- 
tional husbandman (' Aunal. der Preuss. Landwirthschaft,' Janu- 
ary, 1862). 



APPENDIX H (page 237). 

We would earnestly recommend all inquiring travellers in 
other parts' of the world, to endeavour to ascertain, above all 
things, what are the proportions of the annual produce of the 
various cereals and cultivated plants raised in a continued succes- 
sion of crops on unmanured soil of ditferent kinds in the same 
place, and under the climatic influences of widely differing degrees 
of latitude. In so far as the author has been able to obtain re- 
liable information on the matter, from various countries, more 
especially from the torrid zone, a careful examination of the facts 
ascertained would appear to refute everywhere the old wide- 
spread error that a very fruitful soil, under fiivourable climatic 
conditions, in the tropics for instance, will continue inexhaustible, 
even without receiving back from the hand of man the mineral 
matters removed in the crops. Even in the most enchanting lands 
of the tropical zone, on the most fruitful volcanic earth, such as is 
found in the old country of the Incas, the tableland of Quito, 
Imbabura, Eiobamba, Ouenca, &c., a long-continued succession 
of crops drained t!ie soil wherever it was impracticable to convey 
to the fields by artificial irrigation the mud carried down by the 
torrents of the Andes. In those regions water, aided by the wide- 
spread old volcanic mud streams (Lodozales), plays the part, 
which guano and farm-yard manure do elsewhere, of restoring to 
the soil the mineral constituents removed by a continued succes- 
sion of crops. Inmost of the provinces of Persia, more espeei-.lly 
in Aserbeidschan and in a great portion of Armenia and Asia 
Minor, the irrigation c;uuils everywhere met with serve the pur- 



MINERAL MATTKRS SUITLIKD r,Y IRRIGATION. 375 

pose, not so much of moistening the gronnd, as of conveying to the 
land in tlie valleys the mineral detritus washed from the moun- 
tains at the time of the melting of the snow. Tliis method of 
artificial manuring hy irrigation is commonly applied also in 
those countries where there is no lack of rain and dew. It sub- 
serves the same purpose as the mud of the Nile in Egypt, viz. to 
replace the action of farm-yard manure. Where the mineral con- 
stituents removed by a long succession of crops are not restored to 
the ground cither by animal manure, or by irrigation, the soil is 
almost completely drained of its productive powers, as is the case, 
for instance, in certain parts of the extensive tablelands of Tacun- 
ga and Ambato (in the South American State Ecuador), where 
barley will often bai'ely give a two or threefold return, notwith- 
standing the frequent alternations of rain and sunshine. From the 
most reliable information obtained by me, even the most fertile 
estates in San Salvador and Chiriqui, in Central America, with 
their most fruitful, loose, trachytic soil, abounding in potash and 
silica, cannot show a single field on which maize has been grown 
for thirty years running without a considerable reduction of prod- 
uce — a fact which sufficiently refutes the old mistaken notion of 
the inexhaustible fertility of the soil in the tropics. 

On the western coast of Peru only those parts are extremely 
sterile, where no little artificial canals convey to the dry soil the 
water from the torrents of the Andes, which carries with it the 
mineral detritus washed from the declivities of the mountains. 
Wherever sucli artificial canals exist, and the conditions of the 
ground are favourable, the soil on the coast as well as in the interi- 
or of Peru and Bolivia is almost as productive as in the interior of 
the highlands of Ecuador, New Granada, and Gautemala. But it 
is not the water wliich is the agent in maintaining the steady pro- 
ductiveness of the soil, but, as in the case of the Delta of the Nile 
in Egypt, it is the mud carried along with the water, and which 
has been washed away from the disintegrated rocks of the Andes. 
The constituents of this mineral detritus, which are partly con- 
tained in the water in a state of minute mechanical division, and 
partly held in chemical solution, are brought to the fields by small 
channels. The water thus conveyed from the mountains in innu- 
merable furrows is soon absorbed by the soil or evaporated, leav- 
ing a rich fertilising deposit behind. Pure rain Avatcr would be 
of very little avail, as, for instance, in the extensive tableland of 
Tacungar, with its barren pumice stone fields, where (juite near 
the e(iuator rain pours down almost daily during nine months of 
the year. It is not the atmospheric water tluit acts as the fertil- 
ising agent, but the muddy streamlets from the Andes. In Peru 
the fertilising action of guano is more enduring than in England, 
bcpause tlie potash wliich tlie guano does not restore to the soil, is 
there supplied in the detritus from the trachytic constituents of the 
Andes ridge, which abound in felspar. This natural mineral ma- 



376 



APPENDIX I. 



nure is of the same high value in the South American lands of the 
Andes chain as the fertile Loss, accumulated by tlie great flood in 
past ages at the foot of the Bavarian and Swiss Alps. It is a fact 
full of meaning that the inhabitants of those parts of America 
should have arrived at the same simple means of restoring to the 
land the mineral constituents carried away by the crops, which 
are at the present day generally resorted to also under similar 
favourable conditions of tlie ground in the mountainous regions of 
Asia Minor, Armenia, Grusia, "Western Persia, as well as in the 
north of Mesopotamia (Mossul), and, if I mistake not, in Thibet 
also. The waters of the rivers Kur, Araxes, Euphrates and Tigris, 
are in spring just as turbid and as much impregnated with mud, 
■which simply means earthy particles, as the Nile, and as the East 
Persian river Herirud, which it is well known is altogether ab» 
sorbed up in fields and gardens. The experience of ages past has 
no doubt taught the inhabitants of these ancient countries, in both 
hemispheres, this way of restoring to their fields the incombusti- 
ble constituents removed from them in the produce carried away 
to the large towns (Professor Dr. Moritz Wagner; see supplement 
to 'Augsb. Allg, Zeitung,' No. 36, February 5, and No, 173, 
June 22, 1862). 



APPENDIX I (page 321). 

ANALYSIS OF CLOVER MADE BY DR. PINCUS. 

100 parts of air-dried clover contained, — 





Unmanurcd. 


Manured with 
sulphate of magnesia. 


Manured with 
sulphate of lime. 










- 
















a 










































tfl 








M 


a. 




m 


QJ 








3 


^ 




OT 


S 


O 






g 


s 


6= 


2 


a 


« 


't 


u 

a 


s 


S 


1 


"i 




m 


J 


■^ 


K 


a.- 


" 


fa 


H 


OQ 


ij 


fa 




Water 


12-25 
39-55 


13 Ot 

15-07 


15-05 
16-36 


12-95 

■28-8.5 


13-00 
39-47 


14-45 
12-58 


12-12 

17-08 


13-27 
•29-70 


11-85 
38-75 


10-70 
13-73 


12-24 
16-96 


11-60 


Vegetable fibre 


29-8T 


Mineral constituents 


5-05 


1116 


6-32 


6-95 


6-75 


10-97 


7-47 


7-94 


6-65 


11-45 


7-45 


7-% 


Protein substances. 


1015 


•22-08 


17-59 


14-70 


11-42 


24-37 


19-59 


15-81 


12-34 


•28-74 


20-57 


17-45 


Hydrate of carbon . 


33-00 


38 -6o 


4* -68 


36-55 


•29-36 


37-63 


43-74 


.33-28 


30-41 


35-38 


42-78 


33-12 




100-00 


100-00 


100-00 


100-00 


100 00 


100-00 


100-00 


100-00 


100-00 


100-00 


100-00 


100-00 


Totalquantity of nu- 


























tritive substances. 


43-15 


60-73 


62-27 


51-25 


40-73 


62-00 


63-33 


49 09 


42-75 


64 12 


63-35 


50-57 


Proportion of the 


























protein substance 


























to the hydrate of 




























1 : 3-25 


1 : 1-75 


1 : 2-54 


1 : 2 46 


1 : 2-57 


1:1-54 


1:2 23 


1:210 


1:246 


1:1-23 


1:2 08 


1:190 







ANALYSIS OF CLOVEK. 



377 



Asii Constituents. 



100 parts of ash contained, — 



Chlorine 

Carbonic acid 

Sulphuric acid 

Phosphoric acid . . . 

Silicic acid 

Potash 

Soda 

Lime 

^lagnesia 

Sesquioxide of iron 



Clover 
uumanured. 



1-113 

21-43 

1-33 

7-97 

2-67 

33-58 

2-12 

21-71 

5-87 

0-94 



99-55 



Clover manured 
with sulphiito 
of uiasnesia. 



1-22 

21-75 

2-36 

8-49 

2-55 

S2-91 

3-03 

20-66 

5-27 

1-22 



99-46 



Clover manured 

■with suli)hatc 

of lime. 



1-73 

19-17 

3-29 

8-87 

3-03 

35-37 

2-73 

19-17 

5-47 

0-94 



99-82 



Calculated upon the Ash free from Carbonic Acid. 



Chlorine 

Sulphuric acid 

Phosphoric acid . . . 

..Silicic acid 

Potash 

Soda 

Lime 

Magnesia 

Sesquioxide of iron 



Clover 
unmanurcd. 



2-46 
1-69 

10-14 
3-40 

42-73 
2-70 

27-62 
7-47 
1-20 



99-41 



Clover manured Clover manured 
with sulphate with sulphate 
of magnesia. of Ume. 



1.56 
3-02 

10-85 
3-20 

42-05 
3-87 

26-40 
6-74 
1-56 



99-31 



2-14 
4-07 

10-97 
3-81 

43-77 
3-37 

23-72 
6-77 
1-16 



99-78 



The vcniai-kable investigations by Dr. Grouven of tlic clover 
disease deserve also a place here. 

The so-called ' clover disease ' manifests itself in the clover 
])lant, at the period of flowering, by the appearance of a nuiltitudo 
of brown spots of ciyptoganiic plants covering stems and leaves. 
The result of the allection is not simply a failure of the clover 
crop, but the produce reaped is unwholesome for cattle. 

In his examination of the diseased clover, Grouven compared 
tlie organic and the ash constituents of the diseased with those of 



378 



APPENDIX I. 



the healthy plant. Both the healthy and the diseased clover 
■were produced from a mixture of seeds of red clover, lucerne, and 
esparsette, such as is usually grown at Salzmunde, where the 
experiments were made. The samples for examination and 
analysis were taken from the field on August 12. The analysis of 
the healthy plant was confined to the determination of the organic 
substances and the amount of ash. 

100 parts of aii'-dried clover-hay contained, — 





Diseased clover. 


Healthy clover. 


Water , 


16-2 

16-7 

3-6 

7-0 

17-9 

31-7 

6-9 


16-2 




11-7 


Fat 


2-8 


Saccharine matter, calculated as starch* 


18-5 
11-3 


Woody fibre 


31-4t 


Ash 


8-1 








100-0 


100-0 



The composition of the ash of the diseased clover was com- 
pared with that of the ash of red clover (Wolff) and esparsette 
(Way). I The ashes were calculated after deduction of carbonic 
acid, sand, clay, and sesquioxide of iron. 





Diseased clover. 
(Gkouven.) 


Eod clover. 
(Wolff.) 


Esparsette. 
(Way.) 


Potash 


3-32 

0-87 

55-71 

13-03 

2-76 

13-46 

5-99 

4-88 


35-5 
0-7 

S2-8 
8-4 
3-5 
3-3 
8-4 
7-0 


35-8 


Soda 


3'5 


Lime , . 


35-9 


Magnesia 


5-5 


Chlorine 


2-0 


Sulphuric acid 


2-8 




9-6 


Silicic acid 


4-3 








200-07 


09-6 


99-4 



Grouven is led to conclude from the result of his examination 
that the primary cause of the clover disease is attributable to a 



* Substances convertible into sugar by sulphuric acid- 
■f- With 0-1 of ash and 0-184 of protein substances, 
j Compare also the preceding analysis by Dr. Pincus. 



CLOVER DISEASE. 379 

change in the chemical composition of the plant, "which again is 
caused by an altered condition of the soil. The very considerable 
deficiency of phosphoric acid and potash in the ash of tlie diseased 
plant is certainly remarkable (' Zeitschrift der landwirthschaft- 
lichen Ceutralvereius der Proviuz lSachseu,1861,' page 73). 



IISTDEX. 



A 



Absorption, power of, in soils, for foot! 
of plants, 75 

-in charcoal, for colonrint? matter 

and gases is a surface attraction, 76 

in soils, is accompanied by chem- 
ical decomposition, 79 

for compounds of soda, and for 

silicic acid, 88, 137 

— varies in each soil, 137 

for potash, 136 

for silicic acid and ammonia, 138 

is inversely as the ditt'usibility 

of food, 137 

shows the depth to which food 

penetrates, 215 

in turf, 112 

— by roots of plants not osmotic, 63 
value of knowledge of to 

asriculturists, 217 

— of nutriment by roots of plants, 94 

— of silicic acid, influence of organic 
matter on the, 89 

— number of soils, meaninc; of, 139 
for ammonia, potash, phos- 
phate of lime, and phosphate of mag- 
nesia and ammonia, 139 

— importance of, to agricultu- 
rists, in 

Agriculture, progress of, impossible if 
dependent on a supply of ammonia, 
304 

— in Europe still young, 233 
Agricultural produce, the permanence 

of, regulated by a law of nature, 232 
Agrostemma cithago, ash of, 226 
Ahrcnd's examination of the oat plant at 

diflcrent stages of growth, 49 
Aloe, food of, stored in leaves, 41 
Alumina in club moss, 71 
Ammonia, absorbed by diflforent soils, 138 

— absorption, number of, 138 

— absorbed strongly in soils, rich in 
humus, 143 

— action of tho salts of, by them- 
selves and in guano, 247, 281, 287 

— action of salts of, on earthy plioi- 
phatcs, silicates, &c., 83 



Ammonia, amountof inrain and dew, 274 

— always iiresent in air, 275 

— calculation of amount of, that would 
be required in Europe, 305 

— compounds of, by themselves not im- 
portant, 301 

— cost of, precludes its extensive use, 
305 

~- comportment of, with arable soil, 137 

— ditrusibility in soils, 88 

— in drain water, 98 

— in lysimeter waters, 99 

— in spring and river water, 103 

— salts of, as food and as means of dis- 
tributing food in soils, 134, 138 

— in farm-yard manure and soils not 
separable by distillation with alkalies, 
295, 298 

— in manures compared with corn pro- 
duced, according to Lawes, 304 

— manufactured too limited in quantity 
to bo trusted to, 305 

— use of, limited by its price, 307 

— nitrite of, formed tiy oxidation, 307 

— loss of, in lime soils, by oxidation, 311 

— theory, 281, 292 

Ammoniacal compounds, experiments 
with, by Schattenmann, 282 

by Lawes and Gilbert, 283 

by Kuhlmann, 28S, 317 

and with guano by the Ba- 
varian Agricultural Society, 285, 317 
Anderson on the growth of turni])s, 34 
Annual plant, growth of, 29, 43, 46 
Antliomis arvcusis, ash, analysis of, 226 
Appendix A, analysis of birch leaves, 
332 

— H, on tho starch in tho stems of 
palms, 335 

— C, Hale's vegetable statics, 336 

— 1), analysis of drainage, lysimeter, 
river, and marsh waters, 341 

— IC, growth of plants in solutions of 
tlieir f lod, 260 

— F, on tho growth of beans in powdered 
turf, 300 

— G, on Japanese husbandry, 301 

— II, on mineral matters supplied by 
irrigation, 374 



382 



INDEX. 



Appendix I, analysis of clover, 378 

Aquatic plants from Ohe and leer, analy- 
sis of ash of, 347 

Arable soil, absorptive power of, 77, 79, 
136 

abounds in nitrogen, 290, 294 

chemical decomposition produced 

by, 79 

formation of, 78 

food present in, in state of physical 

combination, 81 

food present in, in state of chemi- 
cal combination, 82, 83 

mode of estimating nutritive mat- 
ter in, by chemical analysis, 123 

Ash constituents, number necessary for 
the growth of plants, 19 

necessary for the formation of or- 
ganic compounds, 39 

Asparagus, analysis of the ash of, 335 

Average crop, meaning of, 241 

of wheat, rye, and oats, 165 

diminution of, in Hessian Rhine, 

242 



B 



Baden, Grand Duchy of, food of soldiers 

in, 260 
Baker and Jarvis islands, guano, 264 
Barley, action of soda in the production 

of seed in, 319 

— plant, mode of growth of, 155 
Bavarian experiments with salts of am- 
monia and guano, 285 

with sea salt, 317 

with nitrates, 319 

with superphosphates, 148 

Beans, growth of, in powdered turf, 114, 
360 

Beech leaves, analysis of, 332 

Black soil, of Russia, its fertility, 214 

Biennial plants, growth of, 33 

Bineau, amount of nitric acid and ammo- 
nia in rain water, estimated by, 274 

Bogenhauscn, experiments with sea salt, 
317 

witli salts of ammonia and with 

guano, 286 

— soil, amount of nitrogen in, 287 
Bones acted on by steam, 263 

Bone earth, distribution of in the soil 
efl'ected by organic matter, 86 

and guano compared as to rapidity 

and duration of action, 264 

Saxon experiments with, 265 

— • — with salts of ammonia, etieots of 
compared with guano, 247 

Bottger, formation of nitrite of ammonia 

by, 309 
Boussingault, amount of ammonia in air, 

275 
and nitric acid in rain water 

and dew, 275 
— formed in combustion 

of coal gas, 309 

— on the growth of plants without ni- 
trogenous food, 56 



O 



Centnurea, Cyaniis, ash of, 226 

Cereals, meaning of average crop of, 241 

— average crops of in Bavaria, 205 
in Hessian Rhine, 242 

— conditions for their growth, 144 

— change produced in the arable soil by 
the cultivation of, 218 

— cause of diS'erence in corn and straw 
in, 193 

— effect of removing leaves, &c., from, 
before flowering, 43 

— nitrogenous compounds in, not always 
the same, 246 

— influence of litno or magnesia on the 
nitrogenous compounds in, 247 

— influence of temperature on the 
growth of, 48 

— ratio between albuminous and non- 
albuminous constituents in seeds of, 54 

^ increase at first in roots, 48 

— produce of stalks and shoots in pro- 
portion to the developement of roots, 48 

— produce of, with superphosphates, 
148, 151 

compounds of ammonia, 281, 

286, 287, 288 
common salt and nitrate of 

soda, 317 
Charlemagne, records of, 233 
Chemical analysis of soils, limited value 

of, 214 
Clover, analysis of, 376 

— ash, analysis of, 377 

— diseased, analysis of, 377 
ash, analysis of, 377 

— eftbot of gypsum on, 321 

— crojis bear no proiiortion to the sul- 
phuric acid in the experiments of Dr. 
Pincus, 324 

— requires nearly the same constituents 
as the potato, 201 

— and turnips, effect of in opening the 
soil, 97 

explanation of by Lawes and 

Gilbert, 162 
Compensation, law of, 232 
Compost, 146 

Compound manures, action of, not de- 
pendent upon one constituent alone, 

251 
Copper in ash of plants, 69 
Corn, conditions for formation of, 194 
Corn and straw, constituents in soils, 

195 
relative proportions of in cereals 

afiiected by the weather, 188 
in the Saxon experiments, 

193, 198 
Crops reaped afford no indication of 

quantity of nutritive matter in the 

ground, 189 
Cunnersdorf, manure experiments, 186 

— produce of unmanured fields of, 186 

— nearness of food in soil of, 192, 199 

— produce with farm-yard manure, 202 

— increased produce by farm-yard ma- 
nure, 203 



INDEX. 



383 



Cunucrpilorf, eoi), <loiitli to which in.i- 
iiuro iioiiotratos, 217 

— ])roduco with guano compared with 
farm-yard manure, 255 

— produce with boue-carth and com- 
parison with guano, 204 

— produce with rape cake, 268 

— esperimcutg, eflect of tlie nitrogen in, 
270 

D 

Decreasing crops, progi'ess of, 108 
Difl'usion, law of, does not explain the 

absorption of food by roots of plants, 

65 

— csperiments, 68 

DisinlVction of excrements does not af- 
fect tlieir energy, 261 

Distribution of food by chemical and 
meclianical means, 95 

Drainage, eflect of, 98, 102 

— removal of siliceous plants by, 90 

— water, its composition, 98 
analysis of, 341 

does not dissolve the food of plants, 

102, 103, 108 
Duckweed, power of eclection in roots 

of, 04 
Dung, mechanical action of, 147 



E 



Earthy phosphates, 262 

eftect of, less marked in firtt year, 

264 
diffusion of, through the soil, how 

effected, 84, 86, 139 
require the presence of potash and 

silicic acid in the soil, 264 
and guano, comparative experi- 
ments with, 264 
European husbandry, present state of, 

228 
decline of, produced by the system 

of farm-yard manuring, 200 
illustrated by Hessian Rhine 

district, 242 
Excrement, contain ash of food, 181 

— of man, 260 

collection of, in Rastadt, 2C0 

value of, 260 

not injured by disinfecting with 

sulphate of iron, 261 
Exhaustion of soils, its nature, 83, 85, 206 

known by the average crop, 241 

in chemical and agricultural 

sense, 165 

law of, 165 

— retarded by growth of fodder 

plants, 173 

— of wheat, oat, and rye soils, 170, 175 



Fallow, 83 

False teachers in agriculture, 230. 237 

Farm-yard manure, 145 



Farm-yard manure, effect of, varies with 
the composition of the soil, 206 

_ — — depends on the minimum 

nutritive matters in the soil, 207 

its mechanical action, 208 

restores fertility only by sup- 
plying one or more dclicicnt ingre- 
dients of the soil, 207, 221 

law regulating the quantity to 

be applioii, 211 

produce from, 203 

in the Saxon experiments 

not always equal to the quantity ap- 
plied, 203 

why generally useful, 208 

Saxon experiments with, 203, 

211 

manuring system, 184, 218, 227 

change's produced in the com- 
position of the soil by, 218 

final result of, 223 

illustrated in the 

Saxon experiments, 223 

Fodder plants, proportion retained in 
bodies of animals, 219 

transfer food from subsoil to sur- 
face soil, 41 

Fontinalis, antipyretica, ash analysis of, 
347 

Food, physically and chemically com- 
bined in soils, 81 

— not absorbed by plants from solutions 
Tu soils, 93, 102, 108 

— dilTusion of, in soils, how effected, 
84, 87 

by chemical and mechanical 

means, 95 

— closeness of in soils, 192 



G 



Grouvcn, analysis of diseased clover, 378 
Guano, amount of, equivalent to farm- . 
yard manure, 285 

— and bone-earth, effects of, compared, 
264 

— and farm-yard manure, amount of 
phosphates and nitrogen in, 252 

— from Baker and Jarvis islands, 263 

— fertilising action of, attributed to its 
nitrogen or ammonia. 247, 281 

due in many cases to fixed 

constituents, 247 

— deficient in potash, 249 

— and farm-yard manure, effects of, 
compared, 249 

— when its application will be buccoss- 
ful, 251 

— coiitinned use of, exhausts the soil of 
silica and potash, 252 

— mixed with sulphuric acid and turf 
or sawdust, 253 

— jiefuliar effects of, illustrated in the 
Saxon experiments with different crops, 
253 

— and salts of ammonia, comparative 
experiments with, in Bavaria, 285 

Gypsum, 316 



384 



INDEX. 



Gypsum, experiments on clover, 320 

— action of arable eoil on eolutions of 
325 ' 

— effects tile distribution of potasia and 
magnesia in soils, 327 

n 

Horse-chestnut, analysis of asli of leaves 
of, 335 

Human excrements, value of, as manure, 
illustrated at Rastadt, 259 

price of, 259 

not injured by deodorising by sul- 
phate of iron, 261 



Ignorant practical men, 239 

Iodine, different amount in different 

plants, 69 
Iron necessary for plants, 68 
Irrigation, mineral matters supplied in, 

— -water, suspended mud of, most valu- 
able, 375 



Japanese husbandry, 362 

dispenses with cattle feeding, 364 

— soil, 361 °' 

— supply of manure, 365 

— mode of constructing privies, 365 

— mode of preparing excremeuts and 
compost for application in field, 366 

— system of manuring, only one of top- 
dressing, 367 

— system of planting in rows, 367, 372 

— husbandry compared with European, 
369 ' ' 

— tillage of the soil, 370 

— succession of plants illustrated, 373 
Jerusalem artichokes, effect of the cul- 
tivation of, on arable soil, 215 

K 

Knop, experiments of, on growth of 
plants in solutions of their food, 350 

Kolbe, formation of nitrous acid, 309 

Kiititz, \mmanured field produce from 
186 ' 

Kroker, estimation of nitrogen in soils, 

— analj-sis of drainage water, 342 
Kuhlmann, experiments with salts of 

ammonia, 288, 317 

sea salt, 317 

lime, 330 



Large crops indicate the available con- 
dition of the mineral food, 190 

depend on the closeness of the nu- 
tritive substances in the soU (figure), 
190 ' 

Lawes and Gilbert on clover sickness, 
157 ' 



Lawes and Gilbert on reason of the fail, 
ure of the experiments of, 159 

Leaves, principal conditions for the for- 
mation of, 226 

— removal of, from turnips, 42 
Lime alters the condition of the soil, 329 

— beneficial eflect of, 92 

— experinaents with, 329 

— action of, on soils, 90 
on a drained marshy soil, 92 

— water, effect ot arable soils on, 331 
Lysimeter waters, 99 
analysis of, 363 

M 

Magnesia, dispersed in soils by the agency 
of gypsum, 327 

— influence of, on the formation of nitro- 
genous compounds in seeds, 247 

— necessary to plants, 246 
Maize, growth of, in solutions of its 

food, 375 

— in flower, produces seeds if placed in 
water, 52 

Manure, nature of, ISO 

— and tillage, 134 

— change in the classification of, 292 

— beneficial action of, in restoring the 
relative proportions of mineral matters 
in soils, 130 

— excessive use of, gives no advantage, 
207 

— reason of decreasing value of, by sys- 
tem of rotation, 222 

— nitrogen, classification of, 279 

— action of, not always proportional to 
quantity used, 209 

Manured land, produce of, in Saxon ex- 
periments, 203 

Marine plants, power of selection of food 
in roots of, 64 

Matricaria chamomilla, ash of, 227 

Maiisegast, unmanured field, produce 
from, 186 

Mayer, experiments on soils with caustic 
alkalies, 295 

Meadow grass, effect of sea-salt on, 321 

Metals found in plants, 07, 68 

Mineral matters, absorption of, by soils, 
136 

to be restored, vary in different 

soils, 239 

restored by farm-j'ard manure, 219 

lost in crops in the Saxon experi- 
ments, 224 

restoration of all, necessarj-, 239 

Minimum, law of, 207, 210 

Monocarpous plants, have distinct pe- 
riods of growth, 40 

Moss water, analysis of, 372 

N 

Naegeli, experiments on nutrition of 

plants, 112 
Nile, valley of, reason of its permanent 

fertihty, 236 



INDEX. 



385 



Kitrato of ammonia, formation of, SOS 

Nitrate of Boda, 31S 

action of, on earthy phosphates, 

S3 
-■ — experiments on cereals with, hy 

Bavarian Society, 318 
Nitric acid in rain water, 274 
Nilrosien classilication of manures, 279 

— ostoomed chief agent in manures, 278 

— indetiiiite idea of, in manures, 279 

— assimilable and Buaringly assimilable, 
280 

— amount of in soils, 289 

— amount of, in ditVercnt layers of soils 
illustrated in Russian black soil and in 
Cae.'i soil, 294 

— cause of the inactivity of the great 
nia>-8 of, in soils, 302 

— most abundant in the upper ten inches 
of soils, 294 

— in soils and farmyard manure com- 
pared iis to eflfect, 298 

— prolit and lossof, in the Saxon experi- 
ments, 276 

Nitrotjcn compounds, function of, in 

seeds, 58 

in annuals, 58 

in perennials, 60 

in soils bear no ratio to tlieir pro- 
ductive powers, 290 
supposed different forms of, in soils 

as operative and inoperative, 291, 292 
in soils not distinguished by action 

of alkalies, 295 
in farm-yard manure only partly 

separable hy distillation with alkalies, 

298 
in manures and soils, diflerent 

effects of, on what dependent, 299 
Nitrogenous food, experiments on the 

growth of plants without, 56 
removed in crops is more than fully 

restored by rain, 277 
restored to soils by fodder plants, 

310 
Nitrogenous manures not always the 

most efficacious, 271 
effects of, not proportional to the 

nitrogen present, 310 
first ellect of, 312 

— — when required, 310 

Nutritive substances, closeness of in 
soils (figure), 190 

— — proper relative proportions of, 
131 

maximum and minimum of, in 

soils, 207 

minimum of, regulate the crop, 207 

eflect of the absorption of, iu the 

upper layers of the soil, 152 

O 

Oat, food of, derived from arable soil 
(figure), 200 

— ^nd turnip compared, 53 

— several stages of growth of, 49 
Oberbobritzsch, unmanured field, proj 

ucc from, ISO 

17 



Oberschona, unmanured field, produce 

from, ISO 
Organic matter in manure does not ar- 

rcHt exhaustion, 182 
incorporation of in soils improves 

tlieir physical condition, 96 
Osiuosi.-, laws of, 65 



Palms, starch in stems of, 335 

I'eas and barley plant, growth of com- 
pared, 154 

Perennial ])lant, mode of growth of, 29 

Peruvian guano, composition of, 245 

and ash constituents of seeds, dif- 
ference of, 246 

etl'ect of, due to the presence of 

oxalic acid, 247 

moistened with sulphuric acid made 

more quickly available, 248 

Phosphate of lime, ditt'usion of in soil, 88 

Phosphoric acid and nitrogen, proportion 
between in oats and turnips, 52 

Pierre, analysis of soil by, 294 

Pincus, experiments on clover with gyp- 
sum, 320 

Plants, annual, biennial, and perennial, 
vital properties compared, 29 

— annual, mode of growth of, 33 
leafy, mode of growth of, 43 

— biennial, mode of growth of, 34 

— perennial, mode of growth of, 31, 41 

— growth of, without nitrogenous food, 
56 

— growth of in turf, 112 

in solutions of their food, 109 

— underground organs of, 28, 31 

— rich in starch, sugar, and gum, con- 
tain much potash in their ash, 39 

— store up food in certain organs for fu- 
ture use, 41 

Pools, analysis of stagnant water of, 103 
Potash in soils, not always available, 238 

— necessary for vegetation, 246 
Potato, constituents of, 199 

— draws its principal constituents from 
the arable surface soil, 199 

— eflect of the cultivation of, on arable 
soil, 215 

Poudrette, nature of, 258 

Practical men, 236 

their teaching and practice often 

opposed to each other, 314 

Protoplastem of wheat jjlants, propor- 
tion between nitrogenous and non-ni- 
trogenous substances in, 54 



li 



Radication of plants, 20 

importance of a kno'wledge of, 

28 
Rape-cake, its composition, 267 
more diffusible in soils than guano, 

208 
its fertilising action illustrated In 

the Saxon experiments. 208 



386 



INDEX. 



Bastadt, Boldiers' food and excrements, 
259 • 

Restoration, l;nv of, properly interpreted, 

240 
Rlienish Bavaria, exhaustion of eo 1 of, 

235 
River waters, analyses of, 34S 
Roots, absorption of mini rul matters by, 

70, 89 

— absorption of food by, not an osmotic 
process, 65 

— do not ofl'er permanent resistance to 
the chemical action of salts, 68 

— importance of their dcvelopement in 
cereals, 48 

— mode in which they absorb food, 106 

— length of, 28 

— power of selection of food in, 63, 67 

— principal conditions for the formation 
of, 226 

— spread in search of food, 93 
Rotation, succession of crops in, de- 
pendent on the cereals, 227 

— system of, does not ultimately increase 
corn crops, 232 

— general results obtained in the Saxon 
experiments by, 270 

Rye, cultivation of, instead of wheat, 
shows deterioration of soil, 235, 

— soil, 120 

conversion of, into wheat soil, 127 

S 

Sandy soil, productive power of, 141 

and loam compared, 142 

Sap, Hales' experiments on the motion 
of, 338 

Saxon experiments with lime, 330 

on unnianiired land, 18 

with farm-yard manure, 203, 211 

with bone-earth, 265 

with rape-cake, 268 

profit and loss of nitrogen in the 

soil, 276 

Schattenmann's experiments with salts 
of ammonia, 281 

Schmid, on nitrogen in Russian black 
soil, 294 

Schonbein, nitrite of ammonia in oxida- 
tion and combustion discovered by, 
308 

Sea-salt, experiments with, by Kuhl- 
mann, 317 

with cereals, experiments by Ba- 
varian Society, 317 

Seeds, germination and growth of, 20 

— conditions for the formation of, 61 

— etTect of mineral matter on the growth 
of, 57 

— functions of nitrofeuous matter of, 56 

— importance of good, 24 

— selection of, 25 

Silicates, efl'ect of organic matter in soils, 

in the dift'usion of, 89 
Siliceous plants, removed by drainage, 

89 
Silicic acid, deficiency or excess in soils 

injurious, 90 



Silicic acid, excess of, how remedied, 

90 
distribution of, j^romotcd by growth 

of grass, 89 
Soil and subsoil, 75 

— when fertile, 75 

— chemical aiialysifi of, r,o guide to its 
productive power, 74, 118 

— exhausted, how restored to fertility, 
83 

— estimation of substances physically 
combined in, 124 

— for wheat, rye, and oats, 120, 125 

— different layers of, contain food for 
diiJ'erent plants, 155 

— change produced by cereals in, 218 

— composition of, restored by fodder 
plants, 219 

— distillation of, with alkalies, 296 

— from bogs and ditches, fertilising ef- 
fect of, 105 

— exhaustion of, in Rhenish Bavaria, 
235 

— food in, not inexhaustible, 234, 236 

— fertility of, not due to its nitrogen, 
2S9 

— importance of improving the physical 
condition of, 97 

— mineral matters of, lost in corn and 
cattle sold, 220 

— nutritive power of, estimated by 
amount of food physically combined, 
82 

— productive power of, estimated by the 
available nitrogen in form of ammonia 
and nitric acid, 297 

— progress of exhaustion of, 1C6 

— production of corn and straw in, dur- 
ing the progress of exhaustion, 170 

— restoration of productive power to, 
requires nitrogenous as well as miner- 
al food, 309 

— restoration of nitrogenous food to, ef- 
fected by fodder plants, 310 

— permeability of, to manures, 216 

— productive power of, 129 

— proper relation between food elements 
in for fertility, 130 

— upper layers of, retain the dung con- 
stituents, 220 

— saturated with mineral matter, ma- 
nuring with, 145 

— absorptive power of, 77 
effects chemical decomposi- 
tion, 79 

knowledge of, valuable, 217 

— for potash, 128 

for ammonia increased by or 

ganic matter, 143 
for phosphates of lime and 

magnesia, 139 

for silicic acid, 140 

Starch in stems of palms, 336 
Stohmann, experiments on the growth of 

plants in solutions of their food, 356 
Straw, formation of, 194, 197 
Subsoi., accumulation of organic matter 

in, injurious to deep-rooting i^lants, 91 

— period of exhaustion of, 222 



INDEX. 



387 



Subsoil, mineral matter of, supplied to I 
surface soil by fodder plants, 219 

— not reached by mineral matters of 
manures, 156 j 

Superphosphates, 202 

— experiments with, 148 



•1" 



Tillafje, hcnefieial action of, 118 

Tobacco plant, mode of growth of, 43 

quantity of albumen and nicotine 

in. modified by treatment in growth, 
46 

Tscherno-scm, or black earth of Russia, 
nitrogen in, 294 

Turf saturated with food of plants, ex- 
periments with, 112 

Turnips, growth of, 34 

intluenced by removal of leaves, 

42 



U 



Ilnmanured land, experiments in Saxony 
on, 1S6 

produce of, dependent on preced- 
ing crop, 187 



Viilker, absorption of soils for ammonia, 
142 

— analysis of farm yard manure. 147 

— cstiihation of ammonia in farm-yard 
maniire, 298 



W 

Walnut leaves, analysis of ash of, S34 
Water, drainage, lysimeter, jiver and 
marsh, analysis of, 103, 341 

— in soils, contains ditlerenl quantities 
of nutritive )iiatters, 105 

Water, solvent action of, on soils in 

lysimeters, 342 
Way, analysis of drainage water, 341 
Weeds, cause of tlieir production, 225 
AVheat crop, quantity of phosphoric acid 
and polash removed from soil by, as 
compared with rye crop, 123 

— cfl'ect of potash on, 320 

— tield, retardation of the exhaustion of, 
173 

— growth of, 47, 55 

— produce of, from salts of ammonia, 
according to Lawes and Gilbert, 304 

— produce of, with superphosphate of 
hme, 148 

— soil, 120 

exhaustion of, 169 

Winter wheat, mode of growth of, 47 

eflect of temperature on, 48 

Wood, ash, 272 

mixed with earlli for application, 

273 



Zenker, comparative experiments with 

bone-earth and guano, 264 
Zinc in the ash of Viola calaminaria, 69 
Zoeller, experiments on the vegetation of 

plants in turf, 112 

— mode of analysing soils, 124 

— analysis of guano by, 246 
lysimeter waters by, 342. 



D. APPLETON & CO.'S PUBLICATIONS. 



THE 

NEW AMEllICAN CYCLOPJIDIA. 

EDITED BY 

GEOriGE lUPLEY A^D CHAKLES A. DANA. 

PUBLISHED BY 

D. APPLETON & COMPANY, New York 

In 16 Vols. $vo, Dunble Columns, 750 Pages each. 

Price, Clotk, ^3.50 ; S7ieep,%i; Half 3for., $i.50 ; Half Russia, $5 
per Volume. 

.^O-^' 



Every* one that reads, every one that mingles in society, h 
constantly meeting with allusions to subjects on •which hci 
needs and desires further information. In conversation, in 
trade, in professional life, on the farm, in the family, practical 
questions are continually arising, which no man, well read or 
not, can always satisfactorily answer. If facilities for reference 
are at hand, they are consulted, and not only is the curiosity 
gratified, and the stock of knowledge increased, but perhaps 
information is gained and ideas arc suggested that will directly 
contribute to the business success of the party concerned. 

"With a Cyclopasdia, embracing every conceivable subject, 
and having its topics alphabetically arranged, not a moment is 
lost. The matter in question is found at once, digested, con- 
densed, stripped of all that is irrelevant and unnecessary, and 
verified by a comparison of the best authorities. Moreover, 
while only men of fortune can collect a library comi)lete in all 
the departments of knowledge, a Cyclopfedia, Avorth in itself, 
for purposes of reference, at least a thousand volumes, is within 
the reach of all— the clerk, the merchant, the professional man, 
the Airmer, the mechanic. In a country like ours, where the 
humblest may be called to responsible positions requiring 
intelligonce and general information, the value of such a work 
can not be over-estimated. 



2 D. APPLETON & CO.'S PUBLICATIONS. 

PLAN OF THE CYCLOP/EDIA. 

The New American Cyclopaidia presents a panoramic vie\f 
of all human knowledge, as it exists at the present moment. 
It embraces and popularizes every subject that can be thought 
of. In its successive volumes is contained an inexhaustible 
fund of accurate and practical information on Art and Science 
in all their branches, including Mechanics, Mathematics, As- 
tronomy, Philosophy, Chemistry, and Physiology.; on Agri- 
culture, Commerce, and Manufactures; on Law, Medicine, and 
Theology ; on Biography and History, Geography and Ethnol- 
ogy; on Political Economy, the Trades, Inventions, Politics, 
the Things of Common Life, and General Literature. 

The Industrial Arts and those branches of Practical Science 
which have a direct bearing on our every-day life, such as 
Domestic Economy, Ventilation, the Heating of Houses, Diet, 
&c., are treated with the thoroughness which their great im- 
portance demands. 

The department of Biography is full and complete, embra- 
cing the lives of aU eminent persons, ancient and modern. In 
American biography, particularly, great pains have been taken 
to present the most comprehensive and accurate record that 
has yet been attempted. 

In History, the "New American Cyclopfedia gives no mere 
catalogue of barren dates, but a copious and spirited narrative, 
under their appropriate heads, of the principal events in the 
annals of the world. So in Geography, it not only serves as a 
general Gazetteer, but it gives interesting descriptions of the 
principal localities mentioned, derived from books of travel 
and other fresh and authentic sources. 

As far as is consistent with thoroughness of research and 
exactness of statement, the popular method has been pursued. 
The wants of the people in a work of this kind have been care- 
fully kept in view throughout. 

It is hardly necessary to add that, throughout the whole, 
perfect fairness to all sections of country, local institutions, public 
men, political creeds, and religious denominations, has been a 
sacred principle and leading aim. Nothing that can be con- 
strued into an invidious or offensive allusion has been admitted. 



THE NEW AMERICAN CYCLOPEDIA. 



DISTINGUISHING EXCELLENCES. 

"Wliile -vvo prefer that the work siiould speak for itself, and 
that others should herald its excellences, we cannot refrain 
from calling attention to the following points, in which we 
take an honest pride in believing that the New American 
Cyclopa;dia surpasses all others: — 

L In Acctjeact and Freshness of Information. — The 
value of a work of this kind is exactly proportioned to its cor- 
rectness. It must preclude the necessity of having other 
books. Its decision must be final. It must be an ultimatum 
of reference, or it is good for nothing. 

II. In Impartiality. — Our work has undergone the exam- 
ination of Argus eyes. It has stood the ordeal. It is pro- 
nounced by distinguished men and leading reviews in all parts 
of the Union, strictly fair and national. Eschewing all expres- 
sions of opinion on controverted points of science, philosophy, 
religion, and politics, it aims at an accurate representation of 
facts and institutions, of the results of physical research, of the 
prominent events in the history of the world, of the most sig- 
nificant productions of literature and art, and of the celebrated 
individuals whose names have become associated with the 
conspicuous phenomena of their age — doing justice to all men, 
all creeds, all sections. 

III. In Completeness. — It treats of every subject, in a terse 
and condensed style, but fully and exhaustively. It is believed 
that but few omissions will be found ; but whatever topics may, 
through any oversight, be wanting, are supplied in an Appendix. 

IV. In American Character. — The New Cyclopaedia is 
intended to meet the intellectual wants of the American people. 
It is not, therefore, modelled after European works of a similar 
design ; but, while it embraces all their excellences, has added 
to them a peculiar and unmistakable American character. It 
is the production mainly of American mind. 

v. In Practical Bearing. — The day of philosophical ab- 
straction and speculation has passed away. This is an age of 
action. Ciii bono is the universal touchstone. Feeling this, we 
*luive made our Cyclopa3dia thoroughly practical. No man of 
action, be his sphere humble or exalted,can afford to do without it. 



4 D. APPLETON & CO.'S PUBLICATIONS. 

VI. In Interest of Style. — The cold, formal, and re- 
pulsive style usual in works of this kind, has been replaced with 
a style sparkling and emphatically readable. It has been the 
aim to interest and please, as well as instruct. Many of our 
writers are men who hold the foremost rank in general litera- 
ture, and their articles have been chnracterized by our best 
critics as models of elegance, force, and beauty. 

VII. In Convenience of Foem. — No ponderous quartos, 
crowded with fine type that strains the eyes and wearies the 
brain, are liere presented. The volumes are just the right size 
to liandle conveniently ; the paper is thick and white, the type 
large, the binding elegant and durable. 

VIII. In Cheapness. — Our Oyclopaidia has been univer- 
sally pronounced a miracle of cheapness. We determined, at 
the outset, to enlarge its sphere of usefulness, and make it 
emphatically a book for the people, by putting it at the lowest 
possible price. 

Such being the character of the New American Oyclopasdia, 
an accurate, fresh, impartial, comjilete, practical, interesting, 
convenient, cheap Dictionary of General Knowledge, we ask, 
who can aiford to do without it? Can the merchant, the 
statesman, the lawyer, the physician, the clergyman, to whom 
it gives thorough and complete information on every point 
connected Avith their several callings? Can the teacher, who 
is enabled, by the outside information it affords, to make his 
instructions doubly interesting and profitable ? Can the far- 
mer, to whom it offers the latest results of agricultural research 
and experiment? Can tlie young man, to whoni it affords the 
means of storing his mind with useful knowledge bearing no 
any vocation he may have selected? Can the intelligent 
mechanic, who wishes to understand what he reads in his daily 
paper? Can the mother of a family, whom it initiates into the 
mysteries of domestic economy, and teaches a thousand things 
which more than saves its cost in a single year ? In a word, can 
any intelligent American, who desires to understand the insti- 
tutions of his country, its past history and present condition, 
and his own duties as a citizen, deny himself this great Ameri- 
can digest of all human knowledge, universally pronounced the 
best Cyclopaedia and the most valuable work ever published? 



THE NEW AMERICAN CYCLOPAEDIA. 



CONTRIBUTORS TO THE CYCLOP/EDIA. 

Tho best talent in all parts of the country, and many dis- 
tinguished foreign Avriters, have been engaged in the Xew 
American Cyclopaedia. We givo below the names of several of 
the most prominent contributors, from which the public may 
form some idea of the character of the work. 



Hon. GEOncE Bancroft, LL.D., New York. 

Hon. J. II. Baktlett, late U. S. and Mexican Boundary Commissioner, Provi- 
dence, It. I. 

Kev. Henry AV. Bellow3, B.D., New York. 

Hon. Jeremiah S. Black, U. S. Attorney General, Washincrton, D. C. 

Capt. George S. Blake, U. S. Naval Academy, Annapolis, Md. 

Hon. Erastcs Bkooks, New York. 

Edward Brown -Sequard, M.D., London. 

•TonN Esten Cooke, Esq., Richmond, V.i. 

Rev. J. W. CuMMiNGS, D.D., P.-istor of St. Stephen's Churah, New York. 

Prof. Ja.mes D. Dana, LL.D., Yale College, New Haven, Conn. 

Hon. CiTARLES P. Daly, Judge of the Court of Common Pleas, New York. 

Hon. Charles S. Davies, LL.D., Portland, Me. 

Ralph Waldo Emerson, Concord, Mass. 

Hon. Edward Everett, Boston, Mass. 

Pres. C. C. Felton, LL.D., H.arvard University, Cambridge, Mass. 

D. W. FiSKE. Esq., Secret.iry of tho Geographical and Statistic.il Society, New 
York. 

Charles L. Flint, Esq., Secretary of the Massachusetts Beard of Agriculture, 
Boston, M.-.SS. 

John W. Francis, M.D., LL.D. 

Prof. Chandler R. Gil.man, M.D., College of Physicians and Surgeons, New 
York. ■ 

Prof. Henry Goadey, M.D., State Agricultural College of Michigan, Ann 
Arbor, Mich. 

Horace Greeley, Esq., New York. 

George AV. Greene, Esq., New York. 

R. A. Guild, Esq., Librarian of Brown University, Providence, R. L 

Prof. Charles W. TIackley, D.D., Columbia College, New York. 

Hon. .Tames Hall, Cincinnati, Ohio. 

Gerard Hallock, Esq., editor of the '• Journ.il of Commerce," New York. 

Prof. A. W. Harkness, Brown University, Providence, R. I. 

John R. G. Hassard, Esq., New York. 

Charlf.s C. Hazewkll, Esq., Boston, Mass. 

M. Heilprix, Esq., New York. 

Richard Hildretii, Esq.. author of " History of the United States," &c., New 
York. 

Rev. TnoM.\s Hill, President of Antioch College, Ohio. 

Hon. George S. Hillard, Boston. Mas*. 



D. APPLETON & CO.'S PUB'LIOATIONS. 



CONTRIBUTORS TO THE CYCLOP/EDIA. 

J. S. IIiTTELL, Esq., San Francisco, Cal. 
James T. Hodge, Esq., Cooper Institute, New York. 
Prof. L. M. HuBBAKD, D.D., University of N. C, Chapel Hill, N. C. 
Eev. Henuy N. HuDsojf, author of "Lectures on Shakespeare," &c., Litch- 
field, Conn. 
Prof. S. W. Johnson, Tale College, New Haven, Conn. 
J. C. G. Kennedy, Esq., Washington, D. C. 

Hon. John B. Kerr, late U. S. Minister to Central America, Baltimore, Md. 
Eev. T. Stark King, San Francisco, Cal. 
CuAELES Lanman, Esq., Washington, D. C. 
Charles G. Lei,and, Esq., Philadelphia, Pa. 
Prof. James II. Lowell, Harvard Universitj-, Cambridge, Mass. 
R. Shelton Mackenzie, D.C.L., Philadelphia, Pa. 

Eev. H. N. McTyeire, D.D., editor " Christian Advocate," Nashville, Tenn. 
Charles Noediioff, Esq., author of "Stories of the Island World," &c. New 

York. 
Eev. Samuel Osgood, D.D., New York. 

Prof. Tueopiiii.us Parsons, LL.D., Harvard University, Cambridge, Mass. 
Prof E. E. Peasler, M.D., New York Medical College, New York. 
John L. Peyton, Esq., St.auntun, Va. 

William C. Pri.me, author of " Boat Life and Tent Life," &.c., New York. 
J. H. Eat.mond, LL.D., Principal of the Polytechnic Institute, Brooklyn, New 

York. 
George Schedkl, Esq , hite British Consular Agent for Cosia Rica, Staten 

Island, N. Y. 
Prof. Alexander G. Sciiem, Dickinson College, C.irlisle, Pcnn. 
lion. Francis Sohroeder, Jr., late U. S. Minister to Sweden, Paris. 
Hon. William IT. Seward, U. S. Senator from New York, Auburn, N. Y. 
William Gil.more Simms, LL D., Charleston, S. C. 
Prof. IIenky B. Smith, D.D., Union Theological Seminarv, New York. 
Eev. J. A. Spencei!, D.D., author of "The History of the United States,'' &c., 

New York. 
Rev. William B. Sphague, D.D., Albany, N. Y. 
Hon. E G. Sqfier, author of ■" The States of Central America," " Nicaragua," 

&c. 
Alex. W. TirAVEK, Esq., Berlin, Prussia. 
John E. Thompson, Esq., editor "Southern Liteiary Messenger," Eichmond, 

Va. 
Georob Ticknor, LL.D., Boston, Mass. 
Osmond Tiffany, Esq., Springfield, Mass. 

E. T. Tkall, M.D., author of "Hydropathic Encyclopedia," New York. 
Baron De Trobriand, New York. 

W. P. Trowbridge, Esq., U. S. Coast Survey, Washington, D. C. 
Henry T. Tuckeeman, Esq., New York. 

Ale.xander Walker, Esq., editor of the "Delta," New Orleans. 
Charles S. Weyman, Esq., New York. 

Eev. W. D. Wilson, D.D., Hobart Free College, Geneva, N. Y. 
E. L. YouMANS, Esq., author of " The Hand-Book of Household Science," 

New York. 



THE NEW AMERICAN CyCLOP.EDIA. 



OPIXIONS CF THE PRESS AND DISTIXGIISUED MEN. 

lu setting forth wliat the Press think of the New American 
Cyclopasdia, we hardly know where to begin, so numerous and 
flattering are the notices it has received. "We can only give 
here and tliere a brief extract from the leading Keviews and 
Journal, and letters from distinguished men, bearing for the 
most part on special features of the work. 

The work itself no longer needs commendation at our hands, or at any liands. It 
has long since established its worth; and, if there be in it any considerable 
defect, much searcli will be required to fiud it. — Korth American, Philadel- 
phia, Pa. 

The great arts of condensation, of clear perception, and striking exposition of the 
essential parts of llieir suhject have been fully attained; and will give the 
reader a library of universal knowledge in a convenient compass, arranged for 
ready use, and attractively presented in the concise and perspicuous style ap- 
priiprlate to such a work. — Letter from the late Hon. Tiios. II. Benton. 

This work, instead of being a mere dictionary— a stupid epitome of dry facts and 
dates — is made up of attractive and readable matter; scholarly and sparkling 
essays; fresh biogiai)lues of living and dead celebrities; records of important 
discoveries and inventions; and information on every subject that has attract- 
ed the attention of man up to the present period. — Examiner, Poughkeepsie, 

jv. r. 

I feel quite sure tliat it will be marked by distinguished ability, and that, -when 
concluded, it will be a vast storehouse of late and very important information 
—such a work as almost every intelligent person will be glad to have always 
near him for reference. I can only express the hi^pe that so large an under- 
taking may be duly sustained, and crowned with ultimate success.— Letter 
from the Rt. Rev. IIor.\tio Potter, (_Prot. Spis.) Bishop of j\: 5'. 

The editors have done their duty with justice, fairness, and liberalitv We see 
no instance of partisanship or partiality, and, as yet, no proofs of that hostile 
sectionality of which we have hitherto had reason, in all such publications, to 
complain.— J/«rc"ury, Charleston, S. C. 

We esteem it the best and most comprehensive CvclopiEdia that has vet been is- 

sued from the press of this or any other country. -AVjcs, Savann^.h. Ga. 
%Y hen completed, this Cyclopedia will be the most complete library of knowledee 

which has ever been given to the world in the same space since the art of 

prmtmg was discovered.— Cn/o?;, Rovhexter, K Y. 
Its freshness and genor.al thoronglness give it a dechlcd advanta-e over any 

other Cyclopedia of Its class hitherto issued on either side of the Atlantic — 

Daibj Times, N. Y. 

It Is a perfect treasury of knowledge. In all branches of the arts and sciences, la 
literature, history, biography, and geography.-P/7o/, Boston, Mast. 



D. APPLETON & CO.'S PUBLICATIONS. 



OPINIONS OF THE PEES3. 

The scientific arliolcs are evidently tbe productions of learned and accompliRlied 
nieu. Many of the papers deserve especial commendation, as presenting the 
latest develojjments la their various departments of research.— ^Vaiionai Iii' 
telligencer, Washington, D. C. 

Our own country has never before been so fairly or fully represented in any Cy- 
clopEedia. America, her resources, her literature, her politic?, and her repre- 
sentative men receive in this work, at least, their full share of attention. — 
Post, Boston, 3Iass. 

To enumerate one half of its excellences would require far more space than news- 
paper columns alford. To the professional man and the laborer, the citizen 
and the farmer, it is invaluable as an epitome of all useful knowledge. — Lead- 
er, Cleveland, O. 

There is no conceivalile topic which is not here discussed as fully as most persons 
would care to find it. — American Agriculturist. 

It should bo in every family, for in no other shape can so much useful information 
be obtained as cheaply. As a book of reference, it is Invaluable. — Indiana 
Sentinel. 

It is, without doubt, the most complete work of the kind ever published. To 
prepare it, the publishers have culled jnto requisition the talent of some of the 
best men our country aiiords. — Pennsylvanian, riiiladeliiMa, Pa. 

There can be no doubt that, Ri least for the use of American readers, and in some 
respects wherever the English language is spoken, the CycliipKdia will 
GREATLY SURPASS, in Its value as a reference book, any similar compilation 
that has yet been issued on either side of the Atlantic— A'o^'Z/t American 
Review. 

Take it all in all— for the strict purposes of an Encyclopaedia ; for a clear survey of 
all the departments of human knowledge ; for embracing every important 
topic in this vast range; for lucid and orderly treatment; for statements con- 
densed yet clear; for its portable size— not being too large or too small; for 
convenience of reference, and for practical utility, e.-pocially to American 
readers; it is incomimrally the best work in the Engliah language.— N. 
Y. Evangelist. 

It is a most extraordinary effort of genial scholarship and oi multum in pari>o 
erudition. We commend it as a book which tbe world Ins long wanted, and 
which will exert an incalculable influence in Europe as regards creating re- 
spect for solid American learning.- KZ.:/rayA narri.hurgh,Pa. 

It has been truly said that almost every man of note who ever lived and died, of 
whom there is record, has in it a place; every country, provmce race and 
tribe; everv sea, river, lake and island; every science, religion, and, in short, 
almost every noun in the language, is descriptively illustrated in (he most 
complete shape in which the information could be condensed.- Ctac^c, Tole- 
do, 0. 

The various subjects are not treated according to tbe mere routine of technical 
details, or in the settled formularies of professional science, but, while the in- 
formation is full, thorough, and accurate, it is given in a genial and attractive 
style. — Tribune, Mobile, Ala. 



^-^. " 




LIBRARY OF CONGRESS 




OOOat>7it^4gc5 



